NATIONAL RADIO ASTRONOMY OBSERVATORY

FY - 2006 Program Plan NATIONAL RADIO ASTRONOMY OBSERVATORY

Preliminary Program Plan FY2006

O

November 7, 2005

The National Radio Astronomy Observatory is a facility of the National Science Foundation operated by Associated Universities Inc. Table of Contents

Mission Statement...... 1

1. Introduction ...... 3

2. Science Programs in FY 2006...... 13 Overview...... 13 Cosmology and the Early Universe...... 14 Radio Galaxies, Quasars, Active Galactic Nuclei, and Gamma Ray Bursts ...... 18 Nearby Galaxies and the Galactic Center...... 21 Molecular Clouds, Star Formation, and Galactic Structure ...... 23 Pulsars and Other Radio Stars ...... 25 Solar System; Geophysics ...... 27

3. ALMA Construction...... 29 Overview...... 29 ALMA Key Science Objectives...... 29 Accomplishments in FY 2005 by the Bilateral ALMA Partnership...... 31 NA ALMA Plans for FY 2006 ...... 33

4. ALMA Operations ...... 51 Overview...... 51 North American ALMA Science Center ...... 52

5. Expanded Very Large Array ...... 59 Overview...... 59 Phase I Progress ...... 60 Planned Activities for FY 2006 ...... 64 Planned Activities beyond FY 2006...... 65

6. NRAO Facilities...... 67 Green Bank Telescope ...... 67 Very Large Array ...... 90 Very Long Baseline Array...... 101

7. Central Development Laboratory...... 111 Central Development Laboratory Summary ...... 111 Cooled HFET Development ...... 111 MMIC Development...... 114 Millimeter‐Wave Receiver Development ...... 116 Electromagnetics ...... 118 Green Bank Solar Radio Burst Spectrometer (GB/SRBS)...... 120

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Table of Contents

8. NRAO Science and Academic Affairs...... 123 Introduction ...... 123 The Research Staff of the NRAO...... 123 Library and Archives...... 125 Educational Programs ...... 127

9. Observatory Software...... 131 Overview...... 131 Project‐Based Software Development...... 131 Data Storage and Retrieval ...... 138

10. Education and Public Outreach ...... 143 Overview...... 143 FY 2005 EPO Highlights...... 143 FY 2006 EPO Program ...... 146

11. Observatory Management ...... 155 Overview...... 155 Administration ...... 159 Division of Science and Academic Affairs ...... 166 Program Management Office ...... 166 Computing Infrastructure...... 178 Information Infrastructure...... 181

12. Initiatives and Other Activities ...... 185 New Initiatives ...... 185 Charlottesville Facilities...... 192 Spectrum Management ...... 195

13. Implications of Baseline Funding Plan ...... 199 Baseline and Mission Requirement Funding Plans...... 199 Items not Covered by the Baseline Budget ...... 201 Optimal Science Program with Additional Funding...... 202 Mission Requirement Budget...... 206

14. FY 2006 Preliminary Financial Plan...... 207

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Table of Contents

Appendices ...... 215

A. Scientific Staff Research Activities...... 215 Cosmology, Large Scale Structure, Galaxy Formation, and Gravitational Lensing...... 215 Radio Galaxies, Quasars, Active Galaxies, and Gamma‐Ray Bursts...... 220 Normal Galaxies...... 226 The Interstellar Medium, Molecular Clouds, Cosmic Masers, Star Formation, and Stellar Evolution...... 227 The Galactic Center, Pulsars, Novae, Supernovae, X‐ray Binaries, and Other Radio Stars...... 236 The Solar System and other Planetary Systems...... 239 Astrometry...... 240 Instrumentation ...... 242 Algorithm Development...... 244

B. Research Staff...... 247

C. Management Staff ...... 255

D. Committees ...... 259

E. Acronyms and Abbreviations ...... 263

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Mission Statement

Mission Statement

The mission of the National Radio Astronomy Observatory (NRAO) is to design, build, and operate large radio telescope facilities for use by the scientific community; to develop the electronics, software, and other technology systems that enable new astronomical science; to support the reduction, analysis, and dissemination of the results of observations made by the telescope users; to foster the user community; to support the development of a society that is both scientifically and technically literate through educational programs and public outreach; and to support a program of staff scientific research that enables leadership and quality in all these areas.

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1. Introduction

This is a scientifically exciting time for the U.S. astronomy community, especially the National Radio Astronomy Observatory (NRAO). Through the continuing Atacama Large Millimeter Array (ALMA) and Expanded Very Large Array (EVLA) Phase I projects, the NRAO is designing and building major new centimeter, millimeter, and sub‐millimeter wavelength research facilities that will open scientific frontiers for researchers from around the world. NRAO personnel also continue to meet the challenges of developing new capabilities, instruments, software, and operations modes for the existing NRAO facilities. The scientific productivity and impact of the Robert C. Byrd Green Bank Telescope (GBT) continues to grow; the Very Large Array (VLA) remains one of the world’s most productive astronomical research instruments; and the Very Long Baseline Array (VLBA) provides astronomers with the unique capability to probe the universe at sub‐arcsecond resolution.

This first decade of the 21st century is also a time of major budgetary challenges for the U.S. astronomy community. The NRAO’s increasingly constrained budget and expanding responsibilities – enabling research, operating multiple facilities (VLA, VLBA, GBT), managing the EVLA and ALMA construction, initiating ALMA operations, and defining the North American ALMA Science Center – have made for a challenging Fiscal Year (FY) 2005.

The budget challenges of FY 2005 led NRAO senior management to enact a voluntary early retirement program, and to transition several positions from full‐ to part‐time status. Thirteen NRAO employees accepted the Observatory’s early retirement package, and five persons transitioned from full‐ to part‐time employment. These personnel reductions, together with careful management of Observatory priorities, tasks, personnel, and expenses have allowed the NRAO to successfully navigate its FY 2005 budget challenges.

Despite these budgetary challenges and concerns, the NRAO accomplished a great deal in the past year. The NRAO scientific and technical highlights for FY 2005 are briefly summarized below.

FY 2005 Scientific and Technical Highlights

Atacama Large Millimeter Array (ALMA)

The major ALMA accomplishment in FY 2005 was the successful completion of the North American antenna procurement. On July 11, 2005, at the recommendation of the ALMA Director and the ALMA Board, a contract was signed between AUI/NRAO and Vertex Communications Corporation for the design, fabrication, shipping, assembly and delivery of twenty‐five 12m antennas, with options for up to thirty two antennas.

Adrian Russell became the North American Project Manager in FY 2005 and, as one of priorities, led the ALMA Integrated Project Teams (IPTs) through an extensive budget and

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schedule re‐baselining exercise. The AUI Santiago Chile Office grew to meet the increasing demands in Chile. Construction on the Array Operations Site Technical Building began and progress was made on the Contractors’ Camp at the lower elevation Operations Support Facility.

Significant progress was made on the cryostat design, and the Band 3 and Band 6 cartridges. The integrated Transponder for the Digital Transmission System was successfully tested. Key testing and verification of the first correlator boards was completed. The Computing IPT performed detailed user testing of multiple subsystems. The Systems Engineering and Integration IPT made considerable progress in completing the ALMA high‐level requirements documents, ICDs, and systems integration planning and implementation at the New Mexico ATF and in Chile. The Science IPT expanded the Calibration Plan and generated a more complete Commissioning and Science Verification Plan.

North American ALMA Science Center (NAASC)

Since the first ALMA research observing is scheduled to occur in the third quarter of CY 2009, the activities of the NAASC were initiated in FY 2005, and considerable progress was made in defining the NAASC structure, organization, functions, and budget.

Expanded Very Large Array (EVLA)

The fifth year of the EVLA Phase I project, FY 2005, saw the achievement of several key milestones, including the first interferometric fringes between two EVLA antennas. Additional antennas were outfit to the EVLA design, and the fiber optic termination boxes were set at all 72 array stations. The new wideband L and C‐band feeds were successfully tested, are now in production, and are being installed on EVLA antennas. Training of VLA Operators for the EVLA also commenced in FY 2005. The Canadian Partners conducted a successful Critical Design Review for the correlator chip last year, and a comprehensive Preliminary Design Review was undertaken for the entire correlator.

Green Bank Telescope (GBT)

In FY 2005, the GBT was in routine scientific operation from 290 MHz to 48 GHz, was used by numerous astronomers from around the world, and accomplished a wide array of excellent research. More than two dozen new pulsars were detected in the globular cluster Terzan 5, yielding information on the dynamical conditions in the cluster core, as well as the formation and evolution of pulsar binaries. GBT observations of the double binary pulsar J0737‐3039 provided the most stringent test to date of General Relativity in the strong‐field limit. Observations made toward the Galactic Center revealed additional information on the distribution and formation mechanism of the biologically‐significant interstellar molecule

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1. Introduction

glycoaldehyde. In FY 2005, the GBT also detected H20 maser emission from a quasar at a redshift of z = 0.66, ten times more distant than any previously known H20 maser.

GBT instrumentation moved forward in FY 2005. The Q‐band (40 – 52 GHz) receiver was re‐ commissioned. The first two spectral channels of the Ka‐band (26 – 40 GHz) receiver were also completed and commissioned, and initial science observations were performed. The Caltech Continuum Backend (CCB) has been completed and will be commissioned starting December 2005. The CCB is funded through the Observatory’s University‐built Instrumentation Program. Construction of the W‐band (68 – 92 GHz) receiver was initiated in FY 2005, moving the GBT toward increasingly higher frequencies. In the past year, A. Harris (Univ of MD) was awarded an ATI Grant to build a wideband spectrometer (Zpectrometer) for the detection of very high‐ redshift molecular line emission from the earliest galaxies. The NRAO is a co‐investigator on this proposal. Construction of the Penn Array receiver progressed well in FY 2005, culminating in a complete test installation on the GBT in August. The production of a prototype detector array at the Goddard Space Flight Center was a particularly important milestone for this project.

The GBT team’s focus on improving software systems resulted in the release to the user community of both new observing (ASTRID) and data analysis (GBTIDL) applications in FY 2005. Considerable progress was made also on the Precision Telescope Control System (PTCS) project. The impact of the azimuth track deterioration was successfully mitigated throughout the year via a carefully managed program of ongoing maintenance. Most importantly, the design work required for the retrofit of the azimuth track was completed.

Very Large Array (VLA)

The VLA was busy and productive throughout FY 2005. Astronomers studying Sakuri’s Object acquired the first modern observation of a white dwarf re‐igniting after its nuclear burning had ceased, a unique opportunity to study an event that may be a significant source of carbon and carbonaceous dust in the Galaxy. When the soft gamma‐ray repeated SGR 1806‐20 underwent a giant flare, the VLA was the primary tool used by the astronomical community to study the burst’s afterglow. More than thirty three investigators employed the VLA to study and analyze this magnetar. Astronomers also studied the quasar 1148‐5351, the most distant quasar yet found (z = 6.4), demonstrating that the molecular gas plus the presumed supermassive black hole at the AGN core account for the system’s total mass. This single example from the early Universe of a young galaxy with a supermassive black hole but no significant bulge may serve as an important clue to the long‐standing question of whether the black hole or the bulge formed first or coevally.

The VLA Low‐frequency Sky Survey was completed in FY 2005, and a new large program to study gamma‐ray burst afterglows detected by the Swift satellite was begun. The fiber‐optic

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link between the Pie Town VLBA antenna and the VLA was offered to observers again in FY 2005. During a mid‐year antenna re‐configuration, dynamic scheduling was successfully attempted using the VLA and EVLA software systems. Engineering and test support was provided for a 190 MHz system to search for redshifted neutral hydrogen emission from the Epoch of Reionization. A location was selected for the Long Wavelength Development Array (LWDA) at the VLA site, and a successful design review was carried out. The standard Astronomical Image Processing System (AIPS) continues to be supported for the user community. The primary AIPS architect and developer, Eric Greisen, received the American Astronomical Society’s van Biesbrock award for this work. The VLA Data Archive saw heavy use by the community in FY 2005. A complete set of VLA archive data was transferred to the National Center for Supercomputing Applications.

Very Large Baseline Array (VLBA)

As part of a larger, long‐term project, VLBA measurements of the pulsar B1508+55A yielded a precise, direct distance measurement and revealed that its associated neutron star has an extraordinary speed, nearly 1,100 kilometers per second, challenging the latest models of supernova core collapse. Astronomers also used the VLBA to track the motion of the bow‐ shaped wind‐collision region in WR 140, a Wolf‐Rayet / O star binary. Using VLBA observations of water masers, astronomers directly measured the proper motion and rotational motion of the galaxy M33. This is the first proper motion detection of a galaxy that is not a Milky Way satellite, and yielded the first three‐dimensional measurement of the galaxy’s motion in space. Observations for a large VLBA proposal monitoring the structure of active galaxies at 15 GHz continued.

Eight VLBA antennas and the GBT were used to record the faint signals from the Huygens Probe as it descended through the atmosphere of Saturn’s satellite, Titan. In FY 2005, the NRAO accelerated the conversion to Mark 5 digital recording. The major new frequency capability being developed for the VLBA has been the addition of the 80 – 96 GHz receivers. The NRAO instituted the High Sensitivity Array (HSA) of antennas for VLBI in FY 2005, and twenty HSA programs observed radio quiet quasars, super‐starburst galaxies, gravitational lenses, extragalactic water masers, and supernova remnants.

New digital tachometers had been installed on eight of the ten VLBA antennas by the end of FY 2005. All data back to January 2001, and select earlier data, were loaded into the on‐line VLBA data in FY 2005. This archive is seeing significant use by the community.

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1. Introduction

FY 2006 Program Plan Overview

The Observatory’s FY 2006 goals and plans are described in sections 2 through 16 and the five appendices of this Program Plan, and include the key components summarized below.

Next Generation Scientific Research Facilities

• FY 2006 will be another year of major accomplishments for the ALMA Project. The Management IPT will work to finalize the partnership with Japan. The rebaselining activity will be completed. Construction of portions of the Operations Support Facility and the Array Operations Site Technical Building, and antenna pads will be undertaken. The antenna design will move forward through two major design reviews and into fabrication preparation. The Site and Antenna IPTs, the JAO and the antenna contractor will layout and build the Antenna Site Erection Facility. The first two front ends will be delivered for testing on the prototype antennas, and the first complete sets of electronics modules will be delivered to Chile. Integrated testing of the first correlator quadrant will be completed. Substantial prototype antenna integration activity will be undertaken at the Antenna Test Facility, and first fringes are expected on the prototype antennas.

• The North American ALMA Science Center (NAASC) will see a growing emphasis on software testing, community relations, and observing tool preparation in FY 2006. Detailed NAASC plans will be completed in a manner consistent with the ALMA Operations Plan approved by the ALMA Board. Significant effort will be invested in astronomical community relations through the design and sponsorship of science workshops and community town meetings, building interest while managing expectations. Work will continue on the construction of a spectral line frequencies database. NAASC personnel will also focus on advanced data reduction software, observing at the Antenna Test Facility, and education and public outreach.

• The EVLA Phase I Project will convert three additional VLA antennas to the EVLA design and EVLA antennas will begin to be used routine astronomical research at the VLA. The new RFI‐shielded chamber for the EVLA correlator will be fully outfitted. All 72 stations will be cabled, allowing EVLA antennas to be located anywhere in the array. The Canadian Partners will continue the prototype correlator assembly and testing and will achieve integration testing of prototype hardware and software by early fall. The top level end‐to‐end (e2e) architecture will be designed, and agreements with the ALMA Project will be completed that allow reuse of ALMA e2e software at the EVLA.

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1. Introduction

New Capabilities for Scientific Discovery

• The GBT will operate with an impressive instrumentation suite for astronomical observers in FY 2006, including ten receivers from 290 MHz to 50 GHz and multiple detector back‐ends. Additional capability will be added to the ASTRID observing software and the GBTIDL data analysis software. Commissioning will begin on the Caltech Continuum Backend, and the W‐band receiver will be completed. Construction of the Wideband Spectrometer will begin in FY 2006. The Goddard Space Flight Center Penn Array detector recipe is expected to yield an 8 x 8 engineering array for “first light” tests. The contracts for the azimuth track refurbishment project will be let in FY 2006, budget permitting.

• The first of several modified EVLA antennas will be returned to the VLA for observing in early FY 2006. These antennas will have passed their electronics and scientific checkouts, and will be controlled by a hybrid system of VLA and EVLA software. The VLA + Pie Town real‐time link will be offered while the array is in the A configuration. The development of dynamic scheduling will continue. The first VLA observations using the 190 MHz system are expected to occur while the array is in D‐configuration. Installation of the VLA‐hosted prototype station for the LWDA will be completed in FY 2006, and the first interference fringes against VLA antennas at 74 MHz are expected. A new on‐line VLA proposal submission tool will debut. The pilot imaging project for the VLA data archive will be completed. The tenth Synthesis Imaging Summer School will be held in the summer, with co‐sponsorship from the University of New Mexico.

• Conversion of the stand‐alone VLBA to Mark 5 operations will be completed in FY 2006, with all 10 VLBA stations using Mark 5, accompanied by 10 playback devices at the correlator. With the advent of Mark 5 recording, FY 2006 will see an increase in the available VLBA observing time. The fraction of hours spent on scientific observations will increase from 50% to approximately 60%. The High Sensitivity Array will continue in FY 2006, with many research programs using the combined VLBA, GBT, and phased VLA. Participation in the Global VLBI observing sessions that are carried our three times per year will continue. The NRAO will also continue to participate in global 3mm VLBI observations with several observatories in Europe, in addition to the dynamically scheduled VLBA‐only observations. The on‐line VLBA data archive will continue to populated; the entire VLBA archive will be on‐line by the end of FY 2007. Discussions with the Gamma‐ray Large Area Space Telescope (GLAST) project are expected to yield an agreement in FY 2006 for long‐term dedicated VLBA observing time in conjunction with GLAST after its launch in FY 2008.

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1. Introduction

The innovative and forward‐looking scientific research programs that will be conducted on NRAO telescopes in FY 2006 span the range of forefront research topics in astronomy and astrophysics. Irregularities in the Cosmic Microwave Background radiation trace the clumping of mass to form galaxies and clusters of galaxies in the early universe, and sensitive GBT observations will enhance measurements of these irregularities by removing contamination from intervening radio galaxies and quasars. A major VLA / VLBA program will follow‐up on Gamma Ray Bursters (GRBs) discovered by the Swift satellite and image their relativistic jets, thereby testing models for the explosive collapse and the evolution of massive stars over cosmological time scales. High accuracy binary pulsar timing enabled by the GBT’s sensitivity will make the most stringent tests of general relativity in the strong‐field limit, constrain the equation of state of matter at supra‐nuclear densities, and measure the mass distributions of globular clusters. Water megamasers like those in the nearby galaxy NGC 4258 have been discovered in more distant galaxies by the GBT and may be imaged with sub‐milliarcsecond resolution by the VLBA and the High Sensitivity Array (HSA) which includes the VLBA, phasen‐VLA, GBT, Arecibo, and Effelsberg. Such an image can yield the mass of the nuclear black hole, and accurate geometrical distance to the galaxy, a more reliable estimate for the Hubble constant, and constraints on the dark‐energy equation of state. Observers will also use NRAO radio telescopes in FY 2006 to study relatively local astronomical objects. The GBT, for example, will take part in a bistatic radar experiment to image and characterize the lunar regolith to depths exceeding 10 meters. More detail on the FY 2006 science program is contained in Section 2

NRAO staff research programs are detailed in Appendix A, and the research interests of every NRAO staff member are summarized in Appendix B. A detailed description of the Observatory’s FY 2006 program plan for ALMA construction, the NAASC, EVLA Phase I construction, GBT, VLA, and VLBA is given in Sections 3 through 6.

The Central Development Laboratory (CDL) is a vital organizational component of the NRAO. CDL personnel design and fabricate the electronics instrumentation on all NRAO telescopes, including ALMA. In FY 2006, the engineers, scientists, and technicians at the CDL will continue their development of unique cooled HFET amplifiers, millimeter‐wave receivers, MMIC devices, and the wideband components that serve CDL‐developed mixers and amplifiers. The detailed CDL program plan is given in Section 7.

The FY 2006 plans of the Division of Science and Academic Affairs (DSAA) are described in Section 8. Fostering closer ties between the NRAO and the astronomical community, for example, remains a high priority for the Observatory’s scientific staff. The 2006 Jansky Fellowship Program provides outstanding research opportunities for young astronomers that are comparable to those of the Hubble, Chandra, and Spitzer Fellowship Programs.

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1. Introduction

An extensive discussion of Observatory Software is given in Section 9. In recent years, “Data Management” at the NRAO has transitioned from being largely observatory‐based to largely project‐based, with a high level of cooperation among the projects. During the past year, a common high‐level architecture for the “end‐to‐end” features of the observatory’s instruments has been developed.

Section 10 describes the NRAO Education and Public Outreach Division’s ambitious plans for improving public awareness and understanding of astronomy and the NRAO in FY 2006, including improvements to the NRAO web site, and a new, high‐quality, Observatory‐wide brochure. The EPO Division will also continue to design, edit, and publish the quarterly NRAO Newsletter, and will represent the Observatory at the American Astronomical Society meetings, assisting with planned EVLA and ALMA Town Meetings, staffing the press room, and helping users understand the Observatory’s programs, facilities, and capabilities. The Legacy Imagery Project will continue in FY 2006, including the 2nd annual AUI / NRAO Image Contest and an astronomical poster series. The Green Bank Science Center and the VLA Visitors Center will continue to offer numerous well‐designed educational programs for the general public. The EPO education programs are diverse and extensive, and multiple programs for K – 12 students and teachers will again be offered in FY 2006.

As described in Section 11, the Observatory has defined and implemented a more effective and clear management structure, and has made progress in improving its management processes. As FY 2006 begins, the NRAO senior management team and organization will have been in place, and the Program Management Office Web‐Based Business Systems implementation will be well‐defined and underway. The Observatory’s PMO will enable the efficient capture and dissemination of programmatic data and metrics. As the PMO capabilities come on‐line, the Observatory will further strengthen and streamline its program reporting, metrics, assessment, and overall management capabilities. Members of the Observatory management staff are listed in Appendix C.

Section 12 describes the planned activities of the Observatory’s New Initiatives Office, including its participation in the Square Kilometer Array, Long Wavelength Array, Frequency Agile Solar Radio Telescope, Space VLBI, Focal Plane Arrays, and RFI Mitigation Research. Section 12 also describes the status and plans for the Observatory’s Charlottesville facilities, and the planned FY 2006 activities in Spectrum Management.

The FY 2006 baseline funding plan represents an extremely tight budget given the breadth and complexity of NRAO facilities, and the Observatory’s responsibilities to the astronomical community. Section 13 describes the implications of this baseline funding plan for the NRAO and identifies specific improvements that could be achieved with a modestly enhanced FY 2006 NRAO budget, describing the possibilities for optimizing the scientific capabilities of the Observatory’s facilities and better serving the astronomical community. Each of the identified

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improvements would provide direct benefit to the user community in terms of scientific capability, accessibility, infrastructure preservation, or management. The NRAO FY 2006 Preliminary Financial Plan is detailed in Section 14, which includes a comprehensive Work Breakdown Structure (WBS) that has been designed to track and account for every Observatory activity.

Improving communications with the astronomical community remains a high priority for the Observatory, and the NRAO will actively seek to better involve the community in its strategic planning. The astronomical community members who generously serve on the Observatory’s Program Advisory Committee, EVLA Advisory Committee, Visiting Committee, and Users Committee (Appendix D) have provided vital feedback and input to the Observatory. External advice for ALMA is provided by members of the ALMA Scientific Advisory Committee, the ALMA Management Advisory Committee, and the ALMA North American Science Advisory Committee. The inputs from all of these external advisory committees have had a major influence on the nature and scope of the initiatives and programs proposed in this FY 2006 Program Plan.

NSF – AST Senior Review

Midway through FY 2005, the NRAO was notified that a Senior Review would be conducted by the National Science Foundation’s Division of Astronomical Sciences (NSF‐AST). Through the Senior Review process, the NSF seeks to target $30M of annual funding within the AST Division that would be reallocated by 2011 to fund the design and development of high‐priority projects such as the Giant Segmented Mirror Telescope and the Large Synoptic Survey Telescope, and the operation of the Atacama Large Millimeter Array. Guided by the Senior Review, the NSF may make fundamental decisions regarding the selective reduction of its federally‐funded astronomical research facilities.

The Observatory’s Senior Review report, submitted on 31 July 2005, emphasized that all NRAO facilities are state‐of‐the‐art, complementary, the best in their class in the world, and essential elements of the U.S. astronomical research portfolio. Crafting the Observatory’s formal response to the NSF‐AST Senior Review (available on‐line at http://www.nrao.edu) dominated the last half of FY 2005 for the senior management team and the scientific staff, and it is expected that these NRAO personnel will also be required to invest significant time and effort in the FY 2006 activities of the NSF‐AST Senior Review.

As FY 2006 begins, the NRAO anticipates a bright and productive future: EVLA Phase I and ALMA construction are proceeding well; GBT is maturing and producing world‐class scientific research; the VLA remains one of the astronomical community’s most productive scientific instruments; and the VLBA is being upgraded through the introduction of the Mark 5 recorders. The exceptional breadth and depth of the NRAOʹs facilities, and the Observatoryʹs expertise and

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experience in radio‐astronomical science and technology, have taken 50 years to build, resulting in a NRAO that is widely recognized as an essential resource for astronomy in the United States and, indeed, in the world.

The NRAO sees the challenges of the present as necessary steps towards the scientific opportunities of the future. The Observatory’s people are proud of what they have accomplished, and confident of their ability to continue to design, operate, and maintain the facilities demanded by the extraordinary enterprise that is modern astronomy.

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2. Science Programs in FY 2006

Overview

The scientific investigations which are planned for NRAO telescopes in FY 2006 span the range of forefront research topics in astronomy and astrophysics. This section describes a sample of proposals from the entire astronomical community, and a closer look at NRAO staff research is provided in Appendix A. Some highlights:

(1) Irregularities in the Cosmic Microwave Background (CMB) radiation trace the clumping of mass to form galaxies and clusters of galaxies in the early universe. Sensitive observations with the GBT will enhance measurements of these irregularities by removing contamination from intervening radio galaxies and quasars.

(2) The GBT will observe molecular gas in luminous infrared galaxies and quasars at high redshifts to characterize physical conditions and chemistry during the early phases of galaxy formation.

(3) Water megamasers like those in the nearby galaxy NGC 4258 have been discovered in more distant galaxies by the GBT and may be imaged with sub‐milliarcsecond resolution by the VLBA and the HSA. Such an image can yield the mass of the nuclear black hole, an accurate geometrical distance to the galaxy, a more reliable estimate for the Hubble constant, and constraints on the dark‐energy equation of state.

(4) The Swift gamma‐ray satellite was recently launched to detect gamma‐ray bursts (GRBs) from collapsing or merging tars visible throughout the universe. A major VLA/VLBA program will continue to follow up new GRBs and image their relativistic jets, thereby testing models for the explosive collapse and the evolution of massive stars over cosmological time scales.

(5) The sensitivity of the GBT permits pulsar timing with exquisite accuracy. Timing observations in binary pulsar systems will make the most stringent tests of general relativity in the strong‐field limit, constrain the equation of state of matter at supra‐nuclear densities, and measure the mass distributions of globular clusters.

(6) The GBT will take part in a bistatic radar experiment to image and characterize the lunar regolith to depths exceeding 10 meters.

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2. Science Programs in FY 2006

Cosmology and the Early Universe

The measurement accuracy of small‐scale anisotropies in the Cosmic Microwave Background Radiation (CMBR) is currently limited by contamination from the foreground of discrete radio sources, particularly at multipoles l > 2000 where the Sunyaev‐Zelʹdovich (SZ) effect from clusters between us and the last‐scattering surface is expected to contribute a significant signal. The GBT will be used to observe several hundred sources, selected from 1.4 GHz surveys, at 30 GHz in order to estimate their spectral indices and the general properties of the high‐frequency radio source population. Specifically, the GBT will be used to a) “veto” the deletion of many pixels now excluded from CMBR analyses due to the presence of 1.4 GHz sources (most of these are thought to be unimportant at 30 GHz but GBT data are needed to conclusively show which ones do matter); and b) better constrain the contribution of the “residual source” statistical correction. Some of the best constraints at l > 2000 (Fig. 2.1) currently come from the Cosmic Background Imager (CBI) in the 26 to 36 GHz frequency range. Including systematic uncertainties caused principally by discrete sources, the CBI sees a bandpower of 355 ± 120 μK2, which in a full maximum‐likelihood analysis is ~2σ above the expected level of intrinsic anisotropy (~85 μK2), or about 2.9σ above zero power. We expect the GBT results will reduce that uncertainty from 120 μK2 to about 90 μK2 by reclaiming CBI data and reducing the uncertainty in the statistical correction. Equally important, direct 30 GHz measurements with the GBT would conclusively resolve concerns which some in the CMBR community hold in regard to residual source contamination. This work could make the first clear detection of cluster formation at high redshift through the SZ effect and thereby improve our understanding of the history of large‐scale‐structure formation in the Universe. This work and future work like it will also have implications for the next generation of CMBR polarization experiments, which will require far better understanding of foregrounds than presently exists in the microwave regime.

Figure 2.1. Composite of data from several CMBR anisotropy measurements showing the angular power spectrum of the background. The multipole moment l is inversely related to the angular scale. GBT measurements of faint sources at 30 GHz will reduce the uncertainties at l >2000.

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2. Science Programs in FY 2006

A major objective in the next decade of astrophysical research is the detailed characterization of polarized anisotropies in the CMBR. Knowledge of the properties of the foreground through which the CMBR is seen is vital in planning and optimizing CMBR research as well as in data analysis and interpretation. The GBT will be used to measure the 30 GHz polarization properties of several dozen radio sources, since simple extrapolations from existing low‐ frequency data do not yield accurate properties at the higher frequencies used for CMBR research. The GBT will also be used to make a sensitive HI (neutral atomic Hydrogen) map covering a region to be observed by the Planck mission, so that Galactic foreground infrared emission from dust associated with the HI can be characterized with precision.

Scientists from the Smithsonian Astrophysical Observatory are developing a 190 MHz receiving system for the VLA to search for HI in the redshift range z ~ 6 to 6.5 from the Epoch of Reionization of the Universe. They will search for HI emission surrounding the HII regions of quasars, which may have brightnesses of a few to a few hundred milliKelvin. In FY 2006 observations will be made to test the ability of the instrument to achieve noise‐limited deep integrations and to look for the (unlikely) strong‐signal case for HI emission. If the deep integrations are successful, further related observations are likely in FY 2007.

George Gamow originally proposed that the fine‐structure constant α ≈ 1/137 varies with the age or size of the expanding universe, and his suggestion has been repeated in modern quantum theories intended to unify all forces of nature. Variations in α would also affect the redshift z ≈ 1089 of reionization and the interpretation of CMBR fluctuations. There is controversial evidence for such a variation from optical observations of distant astronomical sources. Radio observations of redshifted OH and HI absorption lines are potentially far better indicators because radio spectrometers have higher frequency resolution and the radio lines are intrinsically narrower. Also, systematic errors can be minimized by observing conjugate OH satellite lines, which should come from the same gas. The GBT will be used to measure the fine‐ structure constant by comparing the velocities of OH and HI lines from distant objects. The results should give values of the fine‐structure constant that are more precise by an order of magnitude than the optical data and can test for possible changes in the fine‐structure constant over 80% of the history of the Universe.

Numerous extragalactic “blank fields” have been observed in recent years by a host of ground‐ based and space‐based telescopes (e.g., Chandra, HST, Spitzer, XMM, Subaru, and Keck). Several of these fields will be imaged at high resolution and sensitivity with the VLA in order to probe the star‐forming and AGN populations at high redshifts. Combinations of radio, infrared, optical, and X‐ray data at arcsecond resolution are particularly useful for detecting dust‐obscured galaxies, separating the starburst and AGN populations, and measuring the evolution of the star‐formation rate in the Universe.

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2. Science Programs in FY 2006

The VLA Low‐Frequency Sky Survey (VLSS) is a major 74 MHz survey complementing the much‐used 1400 MHz NRAO VLA Sky Survey (NVSS). It will use more than 600 hours of observing time over several B‐configuration cycles to cover the entire sky north of ‐30 deg declination with 80 arcsec resolution and detect ~105 sources stronger than 500 mJy at 74 MHz. The VLSS is uniquely sensitive to steep‐spectrum radio sources such as high‐redshift radio galaxies, quasars, relic and halo sources in galaxy clusters, and star‐forming galaxies, and it should even detect the continuum emission from about 100 pulsars. Specific scientific goals include discovering the first radio galaxies and large mass concentrations forming near the epoch of reionization, studying interactions between old radio lobes and the hot X‐ray gas in galaxy clusters, discovering pulsars whose emission was missed by traditional searches for periodic pulses, modeling the cosmological evolution of radio sources not biased by Doppler boosting, and disentangling the superposition of sources along complex sight lines through our Galaxy via the contrast between nonthermal emitters and free‐free absorbing HII regions. Figure 2.2 is a small VLSS subimage showing a number of faint radio galaxies and quasars. The VLSS is being made as a service to the astronomical community, and the principal data products are being released to the public as soon as they are produced and verified. See http://lwa.nrl.navy.mil/VLSS/ for the current status of the VLSS.

Figure 2.2. Gray‐scale representation of a 3˚ x 3˚ portion of one of the VLSS survey fields. The faintest detectable source has a flux density of approximately 0.5Jy.

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During the next two years, the GBT will commission the 64‐pixel Penn bolometer array (see http://chile1.physics.upenn.edu/gbtpublic/), the first of an anticipated suite of large‐format focal‐plane arrays. This device will be used at 3 mm wavelength to image Sunyaev‐Zeldovich clusters at redshifts z > 1 to determine the dynamical state of the hot gas and study the signatures of large cavities in cluster gas caused by AGN jets.

The High‐Sensitivity VLBI Array (HSA), including the VLBA, VLA, and GBT, will continue to search for central images to gravitational lenses. These faint images probe the surface density in the central 10–100 pc of the lensing galaxies and also provide information about the possible existence of central black holes. The central density profiles may be compared with the profiles of nearby galaxies measured from Hubble Space Telescope images, thus determining whether the core properties of galaxies at cosmological distances are similar to those found nearby.

Several projects will use the GBT to search for molecular species at high redshifts. Redshifted CO emission from ultraluminous infrared galaxies will give a measure of the mass of molecular gas and allow comparison with local counterparts. A search for HCN will be made from a quasar which may be undergoing a major starburst phase, to trace dense molecular hydrogen gas within star‐forming molecular clouds. This can test whether the molecular properties of early galaxies were similar to those of today’s nearby galaxies. The ammonia molecule is a good tracer of the kinetic temperature in extragalactic molecular clouds, and the GBT will be used to search for its signature in ultraluminous infrared galaxies to estimate the temperature of these objects as a class and obtain information about their evolutionary stage. Ammonia may also be detected in absorption against the radio continuum of galactic nuclei which contain H2O megamasers. The ammonia measurements will directly determine the kinetic temperature of the nuclear gas.

In the near future the GBT will be equipped with a very wide‐band spectrometer, the “Zpectrometer” currently being built in collaboration with the University of Maryland (see http://www.astro.umd.edu/~harris/kaband/). The Zpectrometer will cover the 26–40 GHz band instantaneously and enable the GBT to detect CO (1–0) emission lines from galaxies throughout the redshift range 1.9 < z < 3.4. The GBT will become a “redshift machine” and undertake blind searches for highly redshifted molecules with great efficiency, measuring redshifts of highly obscured galaxies and opening up new areas of research into the chemistry of galaxies when the universe was less than half its current age.

VLA efforts will continue to identify molecules tracing high‐density conditions in galaxies at high redshifts (hence in the early Universe). HCN (1–0) will be sought in galaxies at redshifts near 2.5, while HCO+ will be sought in the Cloverleaf quasar at a similar redshift. Although the EVLA correlator will make spectral searches simpler, the present VLA has roughly the same sensitivity as the EVLA for the 22 GHz spectral‐line observations, so these observations can be done now as well as they will be in five years. Predictions of the abundances of the high‐

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density molecules vary considerably, so the planned observations will help point the way to future studies of star‐forming galaxies at high redshifts, both with the EVLA and with ALMA. OH megamasers are luminous masers produced only in the nuclei of galaxies which are undergoing mergers. The OH emission is always associated with the inner 100 pc of a starburst nucleus in the merger and may in some cases be found in a circumnuclear molecular torus associated with a massive black hole. The GBT will be used to search for OH megamasers in a rich cluster at z ≈ 0.8 which contains several dozen merging gas‐rich galaxies. These observations have the potential to determine the evolution of the major‐merger rate by comparing the number of masers detected at a given redshift to their local incidence. Only the GBT has the combination of frequency coverage and sensitivity required to push the detection of OH megamasers to this redshift.

Radio Galaxies, Quasars, Active Galactic Nuclei, and Gamma Ray Bursts

Because of the need for high angular resolution, most of the research on these objects is conducted with the VLA and VLBA, where imaging on angular scales of arcseconds and milliarcseconds can be achieved. The GBT is used to survey for interesting objects, and in support of long‐baseline interferometry programs, especially where its large aperture can be decisive.

Emission in the 22 GHz H2O line from a “megamaser” in a galactic nucleus provides information on the nuclear torus and black‐hole mass, and it may yield a precise measurement of the distance to the galaxy independent of the usual distance ladder. The first step in this promising research area is to identify galactic nuclei that show maser emission. For this, the GBT is very powerful. It recently discovered H2O maser emission from a quasar at z = 0.66, and it will continue to search for H2O megamasers in a larger sample of quasars at z > 0.4, the minimum distance at which deviations from the Hubble law are observed in supernova experiments. Another program will search for H2O megamasers in Seyfert galaxies at distances d ~ 100 Mpc suitable for measuring the Hubble constant precisely (see Figure 2.3). An accurate measurement of the Hubble constant, in combination with CMBR data from WMAP, will also provide a strong constraint on the dark‐energy equation of state.

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Figure 2.3. The GBT discovery spectrum of the circumnuclear water maser in NGC 6323 at ~ 100 Mpc distance.

The VLA will continue a productive program of multi‐frequency imaging of the radio jets and lobes in X‐ray‐detected clusters of galaxies. In FY 2006 the remaining objects showing X‐ray cavities and apparent shocks, as extracted from the Chandra Archive, will be imaged with the VLA. The detailed studies of over 20 X‐ray clusters will provide a quantitative understanding of the radio/X‐ray interactions, especially the role of the radio jets in disrupting the expected “cooling flows” of gas into the centers of the clusters.

The nearby radio galaxy M87 contains a relativistic jet that observable at X‐ray, optical, and radio frequencies. Jet knot `HST‐1’, which is located some 40 pc from the galaxy nucleus, is now undergoing a radio flare that appears to follow on the heels of a previous flare of X‐ray and optical emission. These flares are thought to be flares of synchrotron radiation that may follow the acceleration of relativistic particles in the knot or a change in the jet’s velocity. The radio light curve of the knot will be observed at high frequencies (8 GHz through 43 GHz) by the VLA and at much lower frequencies (0.3 GHz through 1.4 GHz) but with comparable resolution by the VLBA. The detailed assessment of the multi‐band light curves will be used to assess the particle loss times and determine whether they are caused by expansion of the radiating fluid (and therefore independent of frequency) or by standard synchrotron losses (strongly dependent on frequency). This, in turn, may have a major impact on our understanding of the evolution of radio jets in a host of extragalactic objects.

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Two large VLBA programs have been proposed to study the details of milliarcsecond jets in blazars, objects whose radio emission apparently is dominated by highly relativistic jets aimed very close to our line of sight. A new window on blazar jets will be opened with the launch of the Gamma‐ray Large Area Space Telescope (GLAST) in FY 2008, and each of the large programs will enable conclusions to be drawn regarding the gamma‐ray sources. The two sets of observations will take different approaches. One will focus on repeated imaging of a sample of about 100 strong blazars, including many which are likely to be fairly strong gamma‐ray sources. The other will survey a larger set of up to 1,000 possible blazars, going to considerably weaker radio fluxes and thus sampling objects which are likely to be lower in gamma‐ray luminosity.

The VLBA will be used to survey Sloan Digital Sky Survey galaxies having double‐peaked broad Hα emission lines. These lines are thought to originate within a thousand gravitational radii of the central black hole and could result from the accretion of a star or other object. The VLBA imaging will be used to search for milliarcsecond‐scale radio structures that indicate nuclear activity triggered by the transient accretion event.

Molecular tori in active galactic nuclei (AGNs) are thought to be responsible for the differing appearances of AGNs seen from different directions, a hypothesis (the “unified scheme”) that has been notably successful in explaining some properties of AGNs. Previous surveys for absorption by ground‐state molecular transitions have been mostly unsuccessful, perhaps owing to radiative excitation effects. The VLBA will be used in FY 2006 to search for absorption at 13.4 GHz by the excited OH molecule in the radio galaxy Cygnus A and in the narrow‐line active galaxy NGC 1052. Detected absorption may be used to image the circumnuclear gas dynamics, while a lack of detection would place stronger constraints on models of the molecular torus.

The MOJAVE project (Monitoring of Jets in Active Galaxies with VLBA Experiments; see http://www.physics.purdue.edu/astro/MOJAVE/) will continue through FY 2006. This Large VLBA Program uses multiple‐epoch 15‐GHz imaging observations to study the relativistic jets in 133 quasars and AGN. The monitoring intervals are tailored to the individual sources and range from a few months to more than a year. Primary science goals include understanding the detailed physics of individual sources and evaluating the statistics of superluminal speeds and other structural changes. MOJAVE monitors a sample of sources considerably larger than any previous effort of this type, at more regular intervals, and for the first time includes full polarization information giving new insight into the physics of relativistic jets.

MOJAVE observations have thus far established a strong connection between the polarization properties of the jets and their optical line strength, which are both likely dependent on total jet power. The polarization vectors tend to follow the curvature in the jets, implying streaming rather than ballistic flow. Further evidence for this streaming motion comes from previous

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multi‐epoch VLBA observations of the relativistic jet flow which shows features moving along the curved jet trajectory. The new MOJAVE polarization observations show that the gradient direction of the fractional polarization is precisely aligned with the electric vectors and the direction of the local jet flow, thus providing strong evidence for ordered, transverse shocks in AGN jets.

The VLA will continue its program of rapid responses to a number of gamma‐ray bursts detected with the Swift satellite, which was launched early in FY 2005. The VLA recently has been instrumental in localizing the afterglows of “short” gamma‐ray bursts, those with rather hard gamma‐ray spectra and burst time scales of less than 100 milliseconds. This has led to an apparent confirmation of the model in which these short bursts are caused by the coalescence of two neutron stars or of a neutron star with a black hole. Further observations in FY 2006 will focus on the short bursts as well as those that are nearby (and might then be resolved by VLBI) or quite distant (serving as a probe of distant star formation).

Nearby Galaxies and the Galactic Center

Spiral galaxies in compact groups of galaxies tend to be deficient in HI, though the reason is unclear. Possible mechanisms include gas stripping, tidal shocks, galaxy interactions, and mergers. Previous GBT observations of one such group detected an extremely broad HI line which was not seen in synthesis observations, implying that there may be substantial amounts of neutral diffuse gas in this system. Further observations of a larger sample are planned to determine the prevalence diffuse neutral gas in the intragroup medium of compact groups. This is an important step in understanding the fate of the cold gas stripped from individual galaxies.

Neutral hydrogen emission will be imaged around a selection of galaxies. Five isolated early‐ type galaxies observed with the GBT were found to contain surprising amounts of HI emission. These objects now will be imaged by the VLA in order to determine whether the HI is in tidal tails, thus indicating that the early galaxies are the results of recent mergers, and will constrain the properties of the galaxy progenitors. The blue compact galaxy II Zw44 contains a 0.5 Mpc HI envelope detected by the Arecibo telescope. The structure of this HI envelope, one of the largest known, is unclear. The VLA will be used to image the HI cloud and determine whether the cloud was produced by tidal interactions among members of the galaxy group or is the natal cloud of young galaxies in relatively early stages of formation.

The cores of two nearby starburst galaxies, IC 342 and M82, will be imaged at 10 pc resolution in the light of the HC3N molecule. The images will be used to generate an inventory of massive star‐formation cores in the two galaxies. The locations of the molecular cores will be compared with the locations of intense radio continuum emission from HII regions, super star clusters,

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and supernova remnants, thus providing information about the correlation of the pre‐stellar cores with the locations of massive stars that already have formed. The VLA image of the (5–4) transition of HC3N will be compared with HC3N (10–9) and CO images made by the OVRO to study the variation of excitation and chemical differentiation across the starburst cores.

The VLA will be used in its most compact configuration to make polarimetric images of a number of nearby galaxies. The dwarf starburst galaxy NGC 4214 will be observed by both the VLA and the GBT at several frequencies in order to address the origins of large‐scale magnetic fields in dwarf irregular galaxies. The 10 kpc ring of the Andromeda Galaxy in the local group will be searched for turbulent magnetic fields, following the suggestion that these fields may indicate the locations of shocks which accelerate cosmic rays and heat the gas in spiral galaxies.

VLBI imaging of nearby starburst galaxies such as Arp 220 will continue, usually with the High Sensitivity Array or global VLBI arrays. This imaging will be used to conduct censuses of young supernovae, detect new supernovae, and provide rough age‐dating of super star clusters by the presence or absence of radio supernovae.

Several recent supernovae in nearby galaxies will be imaged this year with the VLBA, High Sensitivity Array, and global VLBI arrays. Supernova 2001em, in a galaxy at 80 Mpc distance, will have its expansion imaged in order to determine its possible relation to gamma‐ray bursts; it has been speculated that this supernova is related to a gamma‐ray burst seen off axis, and thus should undergo relativistic expansion of the entire object or of an ejected blob of material. The famous supernova 1993J in M81 will be imaged to study the hydrodynamic instabilities at the edge of the shell, explore the particle acceleration process, and search for an emerging pulsar wind nebula within the remnant.

The VLA will continue a systematic program of investigating the radio emission from nearby Type Ibc supernovae. At least a few of these objects appear to be related to gamma‐ray bursts, and apparently contain a broad diversity of radio light curves and inferred ejecta energies. The relation between the Type Ibc supernovae and gamma‐ray bursts will be studied in the context of the “collapsar” model for the sub‐population of long gamma‐ray bursts.

Magnetic fields support the interstellar medium against gravitational collapse, distribute energy from supernovae, channel gas flows, and possibly provide a heating mechanism for interstellar gas. And yet, the process in galaxies which generates and sustains magnetic fields is still unknown. Dwarf irregular galaxies, because of their small size and slow or irregular rotation, would not be expected to show large‐scale, well‐organized magnetic fields, and yet several do. The GBT will be used with the VLA to make observations of the magnetic field in two dwarf irregular galaxies to study structure of the field over a large range of angular scales at several frequencies. This will test the effects of a central bar, the star formation rate, compression of gas by shocks, and the presence of a synchrotron halo on properties of the field.

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A multi‐configuration, large‐scale imaging survey of the Galactic Center region will provide a mosaic of the central 2 degrees of our Galaxy. The new 330 MHz imaging will be used to search for low brightness supernova remnants and other related structures near the heart of the Milky Way. Follow‐up VLA observations also will be carried out to attempt to recover the mysterious transient source discovered last year. This object, located just over 1 degree from the Galactic Center, flared at five 77‐minute intervals during 2002, and recently was recovered in data taken by the Giant Metrewave Radio Telescope just a year later. At present, its nature is unknown.

New 86 GHz VLBA observations of the Galactic Center source Sgr A* will be carried out during the winter observing season. Recent analyses have inferred sizes of just a few tens of Schwarzschild radii for this radio source at frequencies up to 43 GHz, but sophisticated amplitude closure analysis has been required to deconvolve the intrinsic radio source from the scattering disk caused by ionized material in the Galactic Plane. Observations at 86 GHz are considerably less affected by scattering, but suffer because of the effects of the Earth’s atmosphere at the low elevation of the Galactic Center as seen by the VLBA. Installation of an 86 GHz system on the newly improved Brewster antenna should improve the North‐South imaging capabilities of the VLBA for the Galactic Center, and hence confirm, refine, or refute the result found at lower frequencies.

Molecular Clouds, Star Formation, and Galactic Structure

The GBT will be used to search for several interstellar molecules which may be precursors of biologically significant molecules. The molecule CNCHO may tie together the formation of large biomolecules that need a mixture of N and O chemistry. Its detection will give a greater understanding of the chemistry involving C and N species, which to date is very disconnected. Observations of a number of organic molecules in galactic spiral arms will be used to study the physical conditions and chemistry of molecular clouds. An effort will also be made to confirm the possible detection of hydrogen peroxide, H2O2, which is predicted to be abundant on surfaces of dust grains in dense interstellar clouds and which might be released into the gas phase in interstellar shocks. As the GBT begins observing in the 3mm band, it will become an ever more powerful tool for investigating interstellar chemistry and its relationship to biology on the Earth and elsewhere.

The delivery of organic molecules to the early Earth by primitive bodies may have triggered the early evolution of life. The sublimation, diffusion, and refreezing of molecules is a method of spreading complex organic biogenic molecules in the outer protostellar system—a mechanism which probably dominated the early evolution of the Earth. Recently, cold gaseous methanol has been detected in the outer disk of a nearby star‐formation region at a location comparable to that of the Oort cloud in our own solar system. The GBT will be used to map a 48 GHz transition of methanol in this disk to constrain the density and abundance of very cold gas. The

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primary source of the gas‐phase methanol is likely to be the outer layers of a flared disk. In combination with other observations and detailed modeling, the GBT data should give unusually well‐determined density, temperature, and abundance constraints on the disk.

Dark clouds and cold protostellar cores will be targets for a host of VLA observations aimed at refining our models of star formation from molecular clouds. Several programs will investigate the distributions of CCS and NH3 within dark clouds. There presently is some evidence that these two molecules are anti‐correlated in protostars on arcminute scales (thousands of AU), and particularly that the CCS becomes depleted about 105 yr after the protostars are formed. Imaging of the CCS on much smaller scales in starless cores will be used to determine whether the anti‐correlation may be caused by internal chemistry of these cores or by shocks from the surrounding regions of star formation. Infrared dark clouds imaged by the Spitzer Space Telescope also will be studied by the VLA in both NH3 and CCS in order to determine whether the ratio of these molecules can be related to the evolutionary states of the infrared dark clouds, thus implying that the [CCS]/[NH3] ratio may be used as a chemical clock in both high‐mass and low‐mass star formation.

The VLBA will be used for astrometric and imaging observations of several star forming regions. Motions of H2O masers in protostellar outflows will be used to study the kinematics of accretion and outflow/jet formation in young stellar objects. Parallax measurements will be used to refine the distance and depth of the Taurus star‐forming cloud. Polarimetric VLBA imaging of H2O masers in protostellar environments will enable measurements of Zeeman splitting and hence of the magnetic fields in these regions. The magnetic‐field contributions are important but poorly known aspects of the entire process of protostellar collapse, and they will be further constrained by the VLBA observations.

A new large VLA project will conduct a radio continuum survey of the northern Galactic Plane region covered by the Spitzer Legacy program GLIMPSE (Galactic Legacy Infrared Mid‐Plane Survey Extraordinaire). The VLA survey of compact ionized sources will complement the Spitzer survey and a near‐infrared color survey of the same region to provide a comprehensive picture of over 30 million constituent objects within the Milky Way galaxy. The primary goal of the radio survey will be the study of massive star formation via the census and study of ultra‐ compact HII regions and massive young stellar objects, though the data also will be publicly available for a wide variety of other uses.

The supernova remnant IC443 will be imaged by the VLA at its lowest frequencies of 74 and 327 MHz. The primary goal will be to search for low‐frequency free‐free absorption on various lines of sight to the supernova remnant. Such absorption may be caused by ionized gas at the boundary between the supernova remnant and a nearby molecular cloud, possibly part of the complex from which the supernova precursor was formed. Thus the identification of free‐free

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absorption will provide additional constraints on the supernova interaction with the molecular cloud and may enable improved modeling of the shock physics in the interaction region.

Pulsars and Other Radio Stars

The GBT is an outstanding telescope for detecting and timing pulsars because it is the largest fully steerable radio telescope, it is protected from radio‐frequency interference (RFI) by the National Radio Quiet Zone (NRQZ) and the surrounding mountains, and it has an excellent suite of pulsar backends. It is being used to make precision tests of Einstein’s General Theory of Relativity (GR) in the strong‐field regime and to constrain the EOS of neutron‐star interiors by determining the moments of inertia of neutron stars. In less than two years, GBT observations of the relativistic binary pulsar J0737‐3039 have provided higher‐precision tests of GR than those obtained from three decades of monitoring the Hulse‐Taylor system PSR B1913+16 which first showed gravitational radiation. GBT timing data have determined the five principal post‐ Keplerian (PK) parameters, the mass ratio of the two pulsars, and their individual masses with an unprecedented accuracy of 0.1%. The neutron stars in J0737‐3039 will merge in only 85 Myr. This short lifetime multiplies by four the expected detection rate for ground‐based gravitational‐wave interferometers such as the Laser Interferometer Gravitational‐Wave Observatory (LIGO). The Shapiro delay calculated from GR for the measured masses agrees with the observed delay within one part per thousand, making this the most stringent check yet on the validity of GR in the strong‐field limit.

GBT observations in 2006 should increase the accuracy of these PK parameters to the point that second‐order terms will be constrained for the first time, and completely new phenomena (relativistic deformation of the A‐pulsar orbit and parameters characterizing aberration and geodetic precession) will be seen. GR predicts that relativistic spin‐orbit coupling will cause the spins of both pulsars to precess about the total angular momentum (primarily orbital angular momentum) vector with periods ~70 yr. GBT observations of this phenomenon should also yield the first measurement of the moment of inertia for a neutron star.

At very high temperatures or densities, matter undergoes a phase transition to a new state, the quark‐gluon plasma (see Figure 2.4), also present in the early Universe. Combining mass and inertia measurements constrains the EOS of matter at pressures and densities much higher than those found in atomic nuclei. Massive and/or rapidly rotating pulsars recently discovered in dense globular clusters by the GBT increasingly constrain the EOS of high‐density matter, by being too massive to be supported by a “soft” EOS or by rotating too rapidly to be stabilized by a soft EOS. The GBT has been uniquely successful in finding millisecond pulsars in globular clusters thanks to its wide sky coverage (including the Galactic Center region richest in dense globular clusters), its high sensitivity, and the 600 MHz of RFI‐free bandwidth at S band (~2 GHz) available only in the NRQZ.

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Figure 2.4. Neutron stars may contain the only high density (high chemical potential) quark‐gluon plasmas in the Universe.

The GBT will make timing observations of PSR J1907+07, a pulsar recently discovered at Arecibo, which is in a relativistic 3.98 hr binary orbit, possibly with a second neutron star. It is the second‐fastest relativistic binary known and may be a young version of the J0737‐3039 system.

Eclipsing binary systems yield information on eclipse mechanisms, pulsar winds, and the nature of the companion stars. Multiple millisecond pulsars in individual globular clusters constrain cluster mass distributions and the mass‐to‐light ratio within cluster cores. Several clusters which are predicted to have among the highest stellar‐interaction rates, yet have only a few known pulsars, will be the targets of deep searches. The GBT at S‐band (2 GHz) offers unprecedented sensitivity for these searches, especially for clusters near the galactic plane having substantial dispersions from the intervening interstellar medium. Continued study of known cluster pulsars in the globular cluster Terzan 5, in which the GBT has now detected 29 pulsars, most of which are in binaries, will give information on the evolution of the binaries and provide tests of general relativity.

The GBT will also be used to search for pulsar companions to very‐low‐mass white dwarfs, which are believed to live in binary systems whose evolution includes a phase of mass transfer onto a neutron star or other degenerate companion. Detection of radio pulses from the dwarf

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companions would test this model and might discover millisecond pulsars which have only recently been spun up.

Young pulsars are of interest because their properties may be closely tied to their origin in core‐ collapse supernovae. Some young pulsars are embedded in non‐thermal radio wind nebulae, but many of the youngest do not have detectable wind nebulae, possibly because they have high magnetic fields and quickly spin down to long periods. The GBT will be used to search for young pulsars toward a set of shell‐type supernova remnants lacking central wind nebulae. Pulsars discovered from this survey would likely have different properties than the better‐ known young objects and will contribute to our understanding of the supernova process.

Solar System; Geophysics

Multi‐configuration imaging of Uranus will be used to track the seasonal changes in the planetary atmosphere. The use of multiple frequencies will allow probes to different pressure levels, providing new information on the depths of the different weather layers in the giant planet atmosphere.

Radio observations of the Sun provide important insights into a wide variety of physical processes in the solar atmosphere, including the structure and dynamics of the solar chromosphere and corona, coronal magnetic fields, and transient energetic phenomena such as flares, radio bursts, and coronal mass ejections. Radio observations also play an important role in probing the outer corona and the inner heliosphere. A number of radio diagnostics that exploit propagation phenomena—e.g., angular broadening and interplanetary scintillations— have been utilized to constrain the nature of the turbulent solar wind. VLA observations have played a prominent role in all of these areas in past years and will continue to do so in FY 2006. It is expected that as the Sun declines from maximum to minimum activity levels, the research focus will turn from energetic phenomena to the quiet Sun.

The GBT will be used with Arecibo to make bistatic radar observations of the Moon at λ = 70 cm in both circular polarizations. These observations will yield images with resolution < 1 km which are sensitive to large rocks and to the electrical properties of the upper 10 m or so of the lunar regolith. These images will be used to study the cratering history of the Moon, the deposition from the great basins across the lunar highlands in particular.

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3. ALMA Construction

Overview

The Atacama Large Millimeter Array (ALMA) will be the premier millimeter and submillimeter telescope in the world. It is under construction in the Altiplano region of northern Chile and, when completed in about 2012, will combine an array of up to 64 12‐m antennas (see detailed information at http://www.alma.nrao.edu/ALMAHandoutApr05.pdf) with an additional compact array supplied by Japan. ALMA will study many fundamental problems in astronomy, such as the origins of planetary systems and the nature of early galaxies.

The ALMA project is an international partnership among Europe, North America, and Japan, in cooperation with the Republic of Chile. The project is funded in North America by the National Science Foundation (NSF) in cooperation with the National Research Council of Canada, in Europe by the European Southern Observatory (ESO) and Spain, and in Japan by the National Institute of Natural Sciences. ALMA construction and operations are led on behalf of North America by the National Radio Astronomy Observatory (NRAO), on behalf of Europe by ESO, and, on behalf of Japan, by the National Astronomical Observatory of Japan.

ALMA will be a truly transformational instrument for studying the cool universe—the relic radiation of the Big Bang and the molecular gas and dust that constitute the very building blocks of stars, planetary systems, galaxies, and life itself. This material typically has temperatures of 3 K to 100 K, resulting in spectral‐energy distributions peaking at submillimeter to far‐infrared wavelengths. Most of the electromagnetic energy in the Universe lies in two thermal components—the cosmic background and the far‐infrared background—within the ALMA wavelength range λ=1 cm to 0.3 mm (30–950 GHz). Indeed, the peak of the spectral‐ energy distribution for dusty objects in the distant universe is redshifted entirely to submillimeter wavelengths.

ALMA Key Science Objectives

• The ability to detect spectral‐line emission from CO or CII in a normal galaxy like the Milky Way at a redshift of z = 3, in less than 24 hours of observation. • The ability to image the redshifted dust continuum emission from evolving galaxies at epochs of formation as early as z = 10. • The ability to image the gas kinematics in protostars and in protoplanetary disks around young Sun‐like stars at a distance of 150 pc (roughly the distance of the star‐forming clouds in Ophiuchus or Corona Australis), enabling the study of their physical, chemical, and magnetic‐field structures and to detect the tidal gaps created by planets undergoing formation in the disks.

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• The ability to provide precise images at an angular resolution of 0.1 arcseconds. Here the term “precise image” means being able to represent correctly, within the noise level, the sky brightness at all points where the brightness is greater than 0.1% of the peak image brightness.

ALMA’s sensitivity to thermal emission from warm dust is extraordinary. At a fixed wavelength of observation, cosmic dimming with increased redshift is naturally compensated by the strongly increasing dust emissivity as a function of emitted frequency. Thus, ALMA takes us from the current regime, where we can study only exceptionally luminous and rare objects, to the point where we can image the dust in typical galaxies having star‐formation rates of just a few solar masses per year well into cosmic reionization in a manner complementary to and competitive with the James Webb Space Telescope (JWST). ALMA represents a step forward of orders of magnitude over current facilities in terms of sensitivity, frequency coverage, spatial resolution, and spectral capabilities. It will be 10–100 times more sensitive and have 10–100 times better angular resolution than any current mm/submm telescope. Part of this comes from the quality of the site, clearly the best in the world for submillimeter astronomy.

Table 3.1 ALMA Technical Specifications Location Atacama desert, Northern Chile, 5,000 m elevation Coordinates 67d 45’ 16” Longitude ‐23d 01’ 22” Latitude (significant EVLA overlap) Telescope Properties Up to sixty‐four 12‐m antennas, plus compact array of twelve 7‐m antennas and four 12‐m antennas Elevation Range 2–90 degrees Slew Rates 6 deg/sec (360 deg/min) Frequency Coverage 31–950 GHz (λ = 1 cm to 0.3 mm) in ten bands (six bands available at first light, ranging from 3 mm to 0.45 mm) Pointing Accuracy 0.6 arcseconds offset pointing, 2.0 arcseconds absolute Field of View of Antennas 19 arcminutes/ ν (GHz) Baseline Range 15 m to 15 km Number of Baselines 2,016 Spatial Resolution 4 arcseconds/ ν (GHz), largest config.; 40 milliarcseconds at 100 GHz or 5 milliarcseconds at 950 GHz Maximum BW, each pol. 8 GHz Point Source rms, 350 GHz 1.6 mJy in 1 second; 8 μJy in 8 hr Maximum Freq.Channels 8,192

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Accomplishments in FY 2005 by the Bilateral ALMA Partnership

The most significant accomplishment of FY 2005 was the successful completion of the North American antenna procurement process. On July 11, 2005, at the recommendation of the ALMA Director and the ALMA Board, a contract was signed between Associated Universities, Inc. (AUI)/NRAO and Vertex Communications Corporation, a division of General Dynamics SATCOM Technologies, Inc. The phased contract is for the design, fabrication, shipping, assembly, and delivery of twenty‐five (25) 12‐m antennas, with options to purchase additional antennas up to thirty‐two (32). The contract Kick‐Off Meeting was held at the contractor’s Texas facility in July. At the close of FY 2005, the design process is progressing well, looking toward a January 2007 delivery of the first unit in Chile.

All Integrated Product Teams (IPTs) have been heavily engaged in FY 2005 in a budget and schedule rebaselining exercise, which is more fully described below under the Management IPT section.

Through the efforts of the Site IPT and the Santiago Chile Office (SCO) contracts also were signed in August 2005 for the construction of the Array Operations Site (AOS) Technical Building (TB) foundation, structure, and shell. This movement toward construction signals the end of a long period of AOS concept development, construction document development, and bidding and the beginning of actual facilities construction at the high site. The Operations Support Facility (OSF) is progressing at the lower site, as well. While the development of the OSF is primarily an ESO task, AUI/NRAO responsibilities include contracting for the construction of the ALMA Camp extension and for security services at the OSF, both of which have progressed in FY 2005.

Also in FY 2005 the SCO accomplished the major task of outfitting the ALMA Central Offices, as well as the co‐located NRAO/AUI Offices, at the El Golf Office Building in Santiago. This work was done in agreement with the JAO. The El Golf office is a leased space and eventually will be vacated for a permanent office location. In addition, the SCO has been responsible for the establishment of a program of support for newly arrived expatriates to help them settle successfully in Chile.

The Front End IPT made steady progress on the Cryostat design and development as well as the Band 3 and Band 6 cartridges. At least one pre‐production cartridge body for each of Bands 3, 6, 7, and 9 was delivered. Lab tests of the prototype Water Vapor Radiometers (WVR) were evaluated and presented at a PDR (preliminary design review) during the third quarter. The WVR PDR was very successful; performance of both the Dicke‐switched WVR (from Onsala Space Observatory) and the correlation WVR (from Cambridge) met project requirements, allowing the selection of the simpler, cheaper Dicke‐switched design.

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The Back End IPT successfully tested the integrated ½ Transponder for the Digital Transmission System. In addition, the Central Reference Generator was reworked to provide an improvement in phase noise performance for the microwave reference input to the laser synthesizer. Also, detailed comparison of Vega 1 and Vega 2 sampler performances allowed a down‐selection of the Vega 1 and Phobos chips which meet systems specifications. In addition, the LO Photonics Lab group completed their relocation from Tucson to Charlottesville, where they are now engaged in completing the LO development.

The Correlator IPT completed a number of items, including bench testing and verification of 100% of the first quarter correlator boards with a few exceptions, receipt of the signal cables for the first quadrant, verification of the Tunable Filter Board (TFB) algorithms in the pre‐prototype card, and testing of the first full prototype TFB card. Testing included the optimization of the TFB card power measurement and requantization stage.

The Computing IPT progressed in user testing of the Offline (AIPS++) subsystem, Pipeline heuristics, the Executive subsystem, the Observing Preparation and Support subsystem ALMA Observing Tool, and the Telescope Calibration subsystem. All tests were successful. Significant effort in FY 2005 was, and continues to be, put into analysis of the computing needs of the Enhanced ALMA, as the bilateral project plus the Japanese addition is known.

The Systems Engineering and Integration IPT made considerable progress in completing the ALMA high‐level requirements documents, interface control documents (ICDs), and system‐ integration planning and implementation, both in Chile and at the New Mexico Antenna Test Facility (ATF), the prototype antenna installation site at the Very Large Array.

The Science IPT produced an updated and expanded Calibration Plan as well as a more complete version of the Commissioning and Science Verification Plan for assembly, integration, verification, and commissioning of ALMA in Chile. The IPT also developed a plan to produce array configurations appropriate for fewer than 64 antennas. Also, the Array Operations Site was re‐staked; old pad location stakes at the high site were removed and replaced with new locations to avoid poor soil and terrain, as well as vizcacha (large burrowing rodents) colonies.

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NA ALMA Plans for FY 2006

Overview of North American Objectives

The NA ALMA project will engage in several top‐level tasks in FY 2006 that have major import for the future of ALMA construction and operations. The most significant event of 2006 will be the most significant event in the history of the ALMA Project: The cost review, marking the end of the rebaselining exercise, will inform decisions on the future scope and budget of ALMA.

The Management IPT will coordinate the response to the Japanese RFQ (request for quote), and complete negotiations leading to the signing of the Memorandum of Understanding (MOU) with Canada. The Site IPT will oversee construction of the AOS Technical Building and antenna pads. The Antenna IPT will move through the antenna design period, including two major design review meetings, and into the fabrication and preparation for shipping to Chile. A coordinated effort among the Site and Antenna IPTs, the Joint ALMA Office (JAO), and Vertex will be required to lay out and build the Antenna Site Erection Facility, the major facility at the OSF level where the Vertex antennas will be assembled. The Front End IPT will complete the design of all front‐end work and deliver to the ATF the first two front ends for testing on the prototype antennas. The Back End IPT will finish the first complete sets of electronic modules for Chile. The Correlator IPT will complete integrated testing of the first quadrant of the correlator and prepare it for shipment to Chile. The Systems Engineering and Integration IPT and Science IPT will be engaged in the prototype antenna integration at the ATF. First fringes will be seen at the ATF during FY 2006. Finally, the Front End Integration Center (FEIC) will be completed in Charlottesville.

Project Management (Management IPT)

The management of the joint U.S.–European project is based on Integrated Product Teams (IPTs) in which the work is executed jointly by the technical teams of both partners. That is, responsibility for specific tasks is assigned, but the overall effort is shared. The ALMA project is managed and administered by the Management IPT made up of project management staff from AUI/NRAO, ESO, and the JAO.

Joint ALMA Office

The JAO was created by the ALMA Board as the central management structure for the ALMA construction phase. The JAO ultimately will have an ALMA Director, Project Manager, Project Scientist, and Project Engineer. The three key JAO positions currently filled are:

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ALMA Director Massimo Tarenghi ALMA Project Manager Anthony Beasley ALMA Project Engineer Rick Murowinski

The JAO, ESO, AUI/NRAO, and NAOJ have reached agreement on an interim arrangement for the JAO Project Scientist. On a rotating basis, the three Regional Project Scientists will perform the duties of the JAO Project Scientist for 4‐month periods. During each period, the incumbent will spend approximately 20–25 days in Chile. This arrangement will last until late 2007, when it is believed that recruitment of a Project Scientist will be facilitated by the beginning of antenna deliveries and commissioning. Al Wootten will initiate this system and will be performing JAO Project Scientist duties until the end of 2005.

North American Project Office

The North American Project Office (NAPO) has been reshaped over the last year. Dr. Adrian Russell, formerly Director of the U.K. Astronomy Technology Centre, assumed the role of North American Project Manager in January 2005. Dr. Russell is supported by the NAPO staff which includes William Porter, formerly the North American Business Manager, who has taken on the additional responsibilities of Deputy Project Manager. Antony Davies assumed the duties of North American Controller in March 2005. The NAPO staff complement is completed by Stefan Michalski, Project Scheduler; Janet Lychock, Project Coordinator; supported by Jennifer Neighbours, Senior Administrative Assistant.

The NAPO is responsible for the oversight and coordination of all North American contributions to the larger ALMA project, as well as coordination and communication with the JAO and ESO.

Project Milestones

The (hundreds of) detailed ALMA project milestones from the Integrated Project Schedule (IPS) are available on request. Key milestones have been pulled out and are distributed throughout this program plan as key objectives. Where these objectives refer to quarters, they are calendar year, not fiscal year. Note that these milestones may be affected by the outcome of rebaselining and the placing of the ESO antenna contract and must, therefore, be regarded as provisional.

Project Management Control System

The two Executives (AUI/NRAO and ESO) have initiated a Project Management Control System (PMCS) for the ALMA project as a whole. The PMCS program is under the control of the JAO and includes both the development of the necessary tools and procedures for tracking the project and the development of a project‐wide IPS. The fully functional PMCS with earned‐

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value reporting will be fully realized in FY 2006. Until the rebaselining exercise is completed and decisions have been made on the scope and budget of the project, full earned‐value reporting will not be possible.

Objective: Ensure that PMCS earned‐value reporting is available by Q1 2006

Major efforts in FY 2006 for the PMCS team will include supporting the completion of the total project rebaselining, and a full cost review.

Rebaselining

In late 2004 a rebaselining of the ALMA project began with the distribution of information and support tools to the IPT leads and deputies. IPTs were requested to clearly define the scope of their activities and deliverables to the baseline 64‐antenna project and to re‐estimate the budget and schedule of their developments. As this information became available during early 2005, project management continuously reviewed the assumed scope and compared it with (a) the baseline definition of the project and (b) the assumptions being made by other IPTs. This was incorporated into a program‐wide review of the costs and implications associated with the baseline 64‐antenna project scope. A preliminary analysis of the overall status was presented to the ALMA Board in Pasadena in early April 2005. Further revision of the cost estimates and statements of work has continued since that meeting, with a major update being presented to the ALMA Board in the Hague in June. This exercise is now complete and results will be scrutinized in depth at the Cost Review in mid October.

Objective: Hold a successful Cost Review of the ALMA project in October 2006

Japan Partnership

An agreement was signed on September 14, 2004 by NSF, ESO, and the National Institutes of Natural Sciences/National Astronomical Observatory of Japan (NINS/NAOJ) to bring the Japanese formally into the ALMA project. The Enhanced ALMA (EALMA), as the bilateral project plus the Japanese addition is known, provides for the Japanese contribution to the project of four additional 12‐m antennas, twelve 7‐m antennas in the ALMA Compact Array (ACA), a separate ACA correlator, and receiver bands 4, 8, and 10. The four 12‐m antennas in conjunction with the twelve 7‐m antennas being built by ALMA‐J is known as the Total Power Array.

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Currently, the JAO and the executives are closely engaged with NAOJ in various ways. A bi‐ weekly telecon is held by the JAO to review EALMA status and issues. NAOJ is fully aware of the budget rebaselining efforts, and PMCS information IPS data are regularly shared and reviewed together. In addition, the IPTs are fully integrated and the Japanese are routinely involved in design development, review, systems engineering, and discussions of, for example, array interaction and sub‐array configuration.

The details of the agreements among the two executives and NINS/NAOJ currently are being negotiated. While the JAO is coordinating the Japanese entry into the project, each executive is responsible for its own agreement with the Japanese; the bilateral management is not involved directly with the executives’ negotiations. No impact on or delay to the bilateral project is allowable due to the executive/Japanese agreements. AUI/NRAO and NINS/NAOJ will finalize their agreement during FY 2006, within the broader context of the Japanese relationship coordinated by the JAO.

Objective: Finalize the agreement between AUI and NINS/NAOJ by Summer 2006 (subject to NAOJ submittal of their final RFQ).

Canada Memorandum of Understanding

An ALMA MOU between the NRAO and the Herzberg Institute of Astrophysics (HIA) and the University of Calgary related to Canadian ALMA Construction‐Phase Work Packages has been under development throughout FY 2005 and is very near completion. This MOU will be signed in early FY 2006. It complements the existing top‐level MOU between the NSF and the NRC. The North American Project Office has been fully engaged in the crafting of the new MOU, which details the value breakdown of the $20M Y2K Canadian contribution to ALMA and allows for the recycling of Band 3 costs as the number of antennas is reduced from 64 to 50.

Objective: Finalize the MOU between the NRAO and HIA by November 2006.

Santiago, Chile Office

The AUI Santiago Chile Office (SCO) has grown to meet the increasing demands for conducting project business in Chile. From the early days of the one‐man operation of Dr. Eduardo Hardy, the SCO has grown to include a Chilean Business Manager, Dr. Mauricio Pilleux, as well as a full complement of support personnel for local administrative, fiscal, and procurement tasks.

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A key task for 2006 will be to continue to support AUI in determining an acceptable method of employing local staff for ALMA.

In FY 2006 and beyond, in addition to the continuing tasks of interacting with the Chilean government on issues related to environment, the land concession, the accreditation of expatriates, and the local scientific community, the SCO will support the NAPO and Site IPT in the completion of the AOS Technical Building (TB) foundation and shell construction, and bid and support the construction of the AOS TB completion package and between 20 and 50 antenna pads at the AOS, and the site road network. In addition, the SCO will be instrumental in procuring and managing the ALMA Camps catering services for provision of food and cleaning services. This major contract will be bid in October 2005, with the contract work to begin in January 2006.

Objective: Support AUI in determining an acceptable method of employing local staff by Spring 2006.

Site IPT

The Array Operations Site (AOS) is at an elevation of 16,500 ft above sea level. The NRAO is responsible for design and construction of the AOS including the TB (Technical Building), the central cluster of antenna foundations, and parts of the infrastructure.

The contract for the construction of the AOS TB foundation, superstructure, and envelope has been signed. Construction began in September 2005, which is early Chilean spring. Mechanical and electrical work for the AOS building is substantially complete. Bid documents in draft for the remainder of the building have been completed and are under review. This work includes all architectural interior furnishings (offices, refuges, first aid station, bathrooms, mechanical rooms, and computer rooms). All technical‐equipment installation, such as HVAC, fire suppression, control systems, and oxygen enrichment are included. Completion of the TB is scheduled for April 2007.

In addition, NRAO is working with ESO to complete the Contractors’ Camp at the OSF level, at an altitude of approximately 9,600 ft. This work involves construction and outfitting of the facilities to be used for housing the many contractors who will populate the site over the next several years of construction. This work is scheduled to be finished by early November 2005.

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From December 2005 until March 2006 the Site IPT will oversee the procurement of the AOS TB furniture, fixtures, and equipment from the U.S. to the Site. This includes HVAC equipment, fire suppression system, control system, oxygen‐enrichment equipment, doors and hardware, bathroom supplies, etc. Other site‐related and construction‐related tasks for FY 2006 include: (1) build the Vertex (the antenna contractor) lay‐down area at the OSF for antenna assembly and testing, to be finished by April 2006; (2) initiate an Invitation for Bids for the construction of the antenna foundations at the AOS, and start in FY 2006 the construction of the first lot of pads. This likely will be the Central Cluster configuration, anticipated from the scheduled starting date of FY 2007, as required by management; (3) construct the necessary antenna foundations for the Vertex erection facility, beginning in January 2006; (4) initiate an Invitation for Bids with Chilean engineering companies for the design of the roads, power distribution, and fiber optics (FO) design at the AOS, beginning in December 2005; (5) initiate a call for bids for the road, power distribution, and FO construction at the AOS. Construction and outfitting will start in FY 2007 and carry on into later years.

Objectives:

• Complete construction of the AOS Technical Building by April 2007.

• Complete construction and outfitting of the OSF Contractor Camp by November 2005.

• Issue Invitation for Bids for AOS road and power design in December 2005.

• Complete procurement of AOS Technical Building outfitting material by March 2006.

• Complete ALMA–supplied site work at the Vertex site‐erection facility by April 2006.

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Figure 3.2. A View of the AOS Technical Building Site at Chajnantor.

Antenna IPT

The ALMA NA project recently secured a new NA Antenna IPT (AIPT) lead, Mr. Jeff Zivick. Mr. Zivick is an experienced engineer who had been working in the Systems Engineering & Integration IPT. His move to the AIPT ensures project leadership and continuity in this important area.

As previously mentioned, AUI/NRAO, at the recommendation of the ALMA Director and the ALMA Board and with NSF approval, on July 11, 2005 signed a contract with Vertex Communications Corporation for twenty‐five (25) antennas with options to thirty‐two (32) units. This action sets in motion a number of other tasks for the AIPT in FY 2006, including coordinating the completion of the redesign of the Vertex prototype antenna. This activity will be punctuated by a Preliminary Pre‐Production Design Review (PPPDR) to be held in January 2006 and a Pre‐Production Design Review (PPDR) to be held in June 2006.

In addition, the NA AIPT is responsible for coordinating with the Site IPT to complete construction of the Vertex antenna‐assembly facilities at the OSF in Chile. This will involve schedule coordination of the site grading in the area designated for the contractor’s Site Erection

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Facility (SEF), installation of the project‐supplied utility connections, and construction of the antenna‐erection pads at the SEF.

Other tasks to be completed in FY 2006 by the AIPT include (1) overseeing complete assembly of the first production antenna, (2) completing the design of the production nutator and delivery of the first unit, and (3) coordinating with the ESO members of the AIPT on the design and manufacture of the antenna transporter.

Objectives:

• Hold the Antenna Preliminary Pre‐Production Design Review in January 2006.

• Hold the Antenna Pre‐Production Design Review in June 2006.

Front End IPT

The front end for each ALMA antenna will be contained in a single cryogenic dewar designed to accommodate ten receiver cartridges, one per wavelength band. Initially only four cartridges will be built, for the bands at 3 mm, 1 mm, 0.85 mm, and 0.45 mm. Current plans are for the 3 mm cartridge to be built in Canada and the 1 mm cartridge to be built at the NRAO Technology Center (NTC) in Charlottesville. The 0.85 mm and 0.45 mm cartridges are the responsibility of the Europeans.

In FY 2006 the NA ALMA Front End IPT (FEIPT) expects to complete all remaining NA Front End design work and fabricate the first pre‐submodules for those presently in prototype phases. In addition, the FEIPT will assemble and test the Front End Test and Measurement System (FETMS) at the NRAO Technology Center (NTC).

Also, the FEIPT will assemble and test the first Front End at the NTC and deliver it to the ATF. This means that all design and compatibility issues arising during assembly and testing will be resolved. The designs for handling Front Ends in Chile will be completed, including the service vehicle and interfaces to the Antenna and Site IPT work.

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Figure 3.3. Vertex Prototype ALMA Antenna at the Antenna Test Facility (ATF), New Mexico.

Additional work by the NA FEIPT in FY 2006 will include (1) initiation of the assembly and test of Front End #3 at the NTC, (2) resolution of all issues regarding the calibration device, solar filter, and start of the assembly and test of a prototype unit, (3) support of the Prototype System Integration (PSI) activities at the ATF with evaluation and first pre‐production Front Ends, and (4) completion of design, fabrication, and initiation of testing of holography equipment for antenna testing at the OSF.

Objectives:

• Approve the final design of the pre‐production front‐end chassis in January 2006.

• Freeze the hardware design of the monitor and control circuit in February 2006.

• Make the NA Front End Integration Center operational in April 2006.

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Figure 3.4. Cryostat #1 and Band 6 Cartridge Test System Electronics in use for early integrated testing of Band 6 Cartridge.

Figure 3.5. Band 6 cartridge #1: warm LO assembly at right and cold SIS mixer assembly at left. Back End IPT

The NA Back End IPT (BEIPT) expects to construct the first complete sets of electronic modules for Chile by the end of FY 2006. The efforts of the past three years to identify and update requirements, design and develop modules, and staff and organize the IPT have culminated in the construction of two complete sets of prototype modules. The modules currently are being tested by the System Engineering and Integration (SE&I) IPT in the lab and will be installed at the ATF for field testing by SE&I IPT starting early in FY 2006.

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The NA BE IPT is divided into five product areas: (1) Digital Transmission System (DTS), (2) IF Processor and Total Power Digitization, (3) 2 GHz LO Reference and Timing, (4) Photonics LO, and (5) racks, bins, modules, and power supplies. Common activities planned for all groups in FY 2006 include updating the backend requirements, completing the testing of products to verify requirements are met, completing the construction and programming of test stands for products, completing the documentation packages as specified in project requirements, finalizing the schedule and budget estimates to support the ALMA‐wide Earned Value Management initiative, improving the risk‐analysis procedures, and completing the implementation of the Quality Assurance Plan.

In the DTS area, the IPT will complete firmware and testing for the DTS transmitter module (1/2 transponder version) and deliver modules to SE&I IPT for integration testing. In addition, the design and construction of the DTS receiver module (1/2 transponder version) will be completed and the modules will be delivered to the SE&I IPT and the Correlator IPT for integration testing. Work will continue on constructing hardware and modules for delivery for the first antenna in Chile in FY 2007.

In the IF Processor and Total Power Digitizer area, the FE IPT will complete testing of the integrated IF downconverter (IFDC) and total‐power digitizer (version B) and deliver to the SE&I IPT for integration testing. In addition, the gain‐ and gain‐equalizer requirements will be identified. Version C of the IFDC will be procured to incorporate new requirements, once they have been identified by the project. Finally, hardware and modules will be constructed for delivery to the first antenna in Chile in FY 2007.

In the 2 GHz LO Reference and Timing area, the IPT will complete testing of revised modules for integration testing by the SE&I IPT. Also, phase‐noise and stability requirements will be identified. Hardware and modules for delivery to the first antenna in Chile in FY 2007 will be constructed as well.

In the Photonics LO area, the IPT will complete testing and revisions, where necessary, to the Line Length Corrector, Master Laser, LO Photonics Receiver, and Slave Laser for integration testing by the SE&I IPT. Also, construction and testing, and if necessary design revision, of the antenna LO cable wrap will be completed. Four wraps will be delivered to the SE&I IPT for integration testing. Design or procurement of the Central Variable Reference (CVR) module will be initiated. Further, achievable phase‐noise and stability requirements will be identified. Photonics distribution equipment for the central building will be designed when the project requirements are finalized. Finally, construction plans for Central LO racks will be completed and the rack and hardware procurement will be initiated for delivery to Chile in FY 2007.

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Figure 3.7. The two IF Downconverter modules on the left replace the eight modules stacked together on the right. The new modules offer improved performance and lower cost.

The IPT will also initiate the procurement of the first antenna racks in FY 2006. All bin and module hardware will be purchased, including rack‐side connectors and inter‐module cabling for antenna racks. The antenna racks will be configured for shipment to Chile for the first antenna in FY 2007. The power‐supply hardware and modules will be constructed for the Central LO and the first antenna. An air‐flow and thermal analysis will be conducted for racks at ½ atmospheres pressure. Coordination with the Antenna IPT will be made to verify cabling interconnections, electrical power loads, and thermal loads of racks at the antenna. Finally, equipment seismic anchoring in the central building will be coordinated with the Site, Correlator, and Computer IPTs.

Objectives:

• Complete the CDR on all BE equipment by October 2006.

• Deliver pre‐production racks to the ATF to support production receiver by August 2006.

• Deliver empty racks to the OSF for “form fit” test in antenna by Aug 2006.

• Ship the LO reference to the OSF for the AIV (assembly, integration, and verification) single‐antenna test by October 2006.

• Test photonic LO prototypes at the ATF by June 2006.

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Correlator IPT

The ALMA correlator performs digital filtering, delay adjustment, and cross‐correlation calculations on the digital signals received at the AOS building, at a rate of 96 Gbit/sec for each of the antennas. The net computation rate for the cross‐correlation section is 1.7 x 1016 multiply‐ and‐add operations per second.

In FY 2006 the ALMA Correlator IPT expects to complete integrated testing of the first quadrant of the correlator, with the exception that production quantities of Tunable Filter Bank (TFB) cards and Data Transmission System (DTS) Receiver cards will not be incorporated. The first quadrant will be disassembled and packaged for shipment to Chile. Depending on the availability of facilities in Chile, the equipment will be either stored in the U.S. or shipped to Chile.

In addition, the assembly of the second quadrant will be completed and significant progress will be made in integrated testing, including early production units of TFB and DTS Receiver cards. Assembly of the third quadrant will begin. Most of the printed‐circuit boards needed to build quadrants 3 and 4 will be received from the commercial manufacturer, and significant progress is planned in bench testing these boards. Also during FY 2006 a production decision will be made for the TFB cards (choosing between a fixed‐program hardcopy version of an Altera Stratix I chip or retention of the flexibility of an FPGA by using a standard Stratix II chip) and production of TFB cards will begin.

Also, the operational software and firmware needed for initial operation in Chile will be verified. Finally, the use of the 2‐antenna prototype correlator for Prototype System Integration at the ATF will be supported by the Correlator IPT.

Figure 3.8. The first quadrant of the correlator.

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Objectives:

• Prepare the first quadrant of the correlator for shipping in June 2006.

• Ship test fixtures to Chile in June 2006.

• Complete assembly of the second correlator quadrant in June 2006.

• Begin integration of the third correlator quadrant in July 2006.

Computing IPT

Within the ALMA Computing IPT (CIPT) the NRAO has primary responsibility for overall IPT management, control and correlator software, offline data reduction (AIPS++), pipeline processing, dynamic scheduling, and software testing. In addition, NRAO personnel participate in the technical development of the ALMA Common Software, high‐level analysis and design, integration test and support, science software requirements, and software engineering. Some additional information on Offline (AIPS++) computing is presented elsewhere in this document.

Several important activities affecting the entire CIPT will occur in FY 2006. The CIPT will provide the software development, testing, support, and documentation required for Systems Integration both in the lab and at the ATF. The most visible output of this process will be in getting to first fringes at the ATF, currently scheduled for June 2006. This will involve finishing the development of outstanding hardware ʺdevice drivers,ʺ testing them in the lab in isolation and in integration. At the ATF the device‐level software will be combined with the higher‐level coordination software (i.e., synchronized with celestial‐source tracking and data taking), and debugged as necessary to achieve SE&I objectives. Also by June 2006 the CIPT will use the ATF as a testbed to check out the entire dataflow (from observing tool to archive to post‐processing), which heretofore has only been tested as an integrated system in a simulation mode. This preparatory work is essential to keep software commissioning off the critical path in Chile. The procedures required for antenna acceptance in Chile will also be checked, and the hardware/software interface control documents (ICDs) (e.g., to the Chilean weather station) will be completed. Before the end of FY 2006, depending on the details of antenna scheduling, the CIPT will make some hardware (control computers, etc.) and software (commissioning software) deliveries to Chile.

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The above activities will be carried out through the production, integration, installation, and testing of a major (December 2005) and minor (June 2006) release, supported by intermediate patch releases and installation of monthly releases as necessary to support the ongoing ATF work. Given the unique characteristics of software development, the CIPT has scheduled a series of yearly incremental CDRs. The fourth of these will occur by June 2006, focusing on design and planning for the coming year. The rebaselining process will be finished, and any follow‐up planning to accommodate changes that occur in that process will be concluded.

A vigorous user test campaign for subsystems with an interface to the user community (e.g., the Archive and Offline subsystems) will be continued, and more integrated system tests will be started. In addition to the ATF tests described above, the CIPT also will test the Archive, concentrating on performance and interface issues. All test results will be publicly accessible.

Objectives:

• Make a major software release in December 2005.

• Make a minor software release in June 2006.

• Support first fringes at the ATF in June 2006.

• Hold an incremental CDR in June 2006.

Figure 3.9. A Sample ALMA Observing‐Tool Screen

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Systems Engineering & Integration IPT

In FY 2006 the ALMA Systems Engineering & Integration (SE&I) IPT expects to release the updated Version B of the ALMA System Technical Requirements. This document will link the science requirements and the sub‐system technical requirements and will be consistent with both. The remaining Interface Control Documents (ICDs) for both the baseline ALMA and the Japanese Enhanced ALMA will be completed and released.

The SE&I IPT will complete the ALMA requirements analysis and release the system performance budget document in FY 2006. The reliability analysis of the electronics system also will be completed.

In addition, the lab phase of the prototype system integration and testing will be completed, and the full prototype electronics system and control software will be installed on the ALMA antennas at the ATF. Phase coherence and interferometric fringes will be obtained on the prototype systems at the ATF. Prototype system functionality will be verified.

Further, the SE&I IPT will replace the prototype electronics systems at the ATF with the first pre‐production Back End and Front End systems. Verification of pre‐production system functionality will begin. Finally, detailed planning of antenna integration and verification in Chile will begin.

Objectives:

• Begin detailed planning of antenna AIV (assembly, integration, and verification) in Chile in January 2006.

• Install full electronic system and control software on ATF antennas in January 2006.

• Obtain first fringes at the ATF by June 2006.

• ICDs for baseline and Enhanced ALMA substantially complete by July 2006.

• Release system performance budget document in March 2006.

Science IPT

In FY 2006 the ALMA Science IPT expects to document all remaining secondary science requirements for items such as the calibration device, solar filter, and Band 7 quarter‐wave

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plate. In addition, all aspects of the ALMA configuration redesign, including simulations, will be completed.

The IPT will support Prototype System Integration activities at the ATF with evaluation of the prototype ALMA interferometer and will begin implementation of the ALMA Calibration Plan at the ATF facility.

In addition, the ALMA Water Vapor Radiometer will be implemented at the Submillimeter Array (SMA) on Mauna Kea and phase correction will be demonstrated.

Further, the Science and Imaging IPT will increase community involvement with ALMA through the AAS town meeting, ALMA workshops at the NAASC (such as “From z‐machines to ALMA” in January) and at other venues.

Objectives:

• Deliver the final long‐baseline configuration in December 2005.

• Deliver all remaining baseline configurations in September 2006.

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4. ALMA Operations

Overview

No telescope in operation or under construction has the power ALMA will have for imaging the formation and evolution of protostars and galaxies, for detecting and studying starburst galaxies at high redshifts, or for analyzing the chemistry and physical conditions of interstellar clouds. ALMA will be the first NSF astronomical facility with an end‐to‐end data system that runs from observing time proposal to finished data products delivered to the observer, ALMA data archive, and National Virtual Observatory.

ALMA observing is to begin in the third quarter of CY2009 with an initial array of eight antennas, each with four receiver bands, and the first quadrant of the correlator. This milestone sets the schedule for completion of all systems required for observers to submit proposals for early science programs; to referee, rank, select, and schedule proposals; to verify array operations and data quality; to archive data and distribute data to observers; and to assist observers with the further analysis of data. The construction of the software for these functions is a task of the ALMA construction team. The testing and evaluation of these software systems is an operations task, one that began in FY 2005 to meet the early‐science milestone. These tasks belong to the ALMA Regional Centers (ARCs). The North American ARC is contained within the North American ALMA Science Center (NAASC), located at the NRAO in Charlottesville, Virginia. The activities planned for the NAASC, particularly in FY 2006, are presented below.

Preparing for ALMA operations consists of more than preparing for early science. Commissioning the array in Chile is a major operations task. Antennas will be assembled and equipped with instrumentation at the Operations Support Facility (OSF) by the ALMA construction team. Upon certification that it is operational within specifications, the antenna is turned over to ALMA operations for transport to the array site, installation on an antenna pad, and connection to the permanent local‐oscillator and intermediate‐frequency systems. It is an operations task to establish the overall system performance of antennas and correlator and to conduct tests of the array as an interferometer. As the array becomes operational, early science programs can be conducted, interspersed with testing and debugging. Antennas will be added to the array in sets of eight as each set is commissioned. This major task belongs to ALMA operations in Chile, which has the responsibility for directing all ALMA operations including coordination with the ARCs in North America and Europe.

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North American ALMA Science Center

The NAASC is the access portal to ALMA for the North American scientific community. In the context of the NRAO, its closest parallel is a telescope operating site such as Green Bank or Socorro. The user support facilities of the NASA space telescopes (Hubble, Spitzer, Chandra) are better analogs. The NAASC will be the point of contact for North American ALMA users from proposal submission to calibrated‐data distribution and analysis. The heart of this end‐to‐ end data system will be a data archive. Much of the Center’s activity will be the development and maintenance of the pipeline reduction, archiving of data, and software systems that surround it. The NAASC will conduct a program of ALMA Fellows and provide support for data analysis by users. It will be the focus for ALMA affairs in North America, sponsoring workshops, schools, and events that foster community development and guide the future evolution of ALMA. ALMA development projects, both hardware and software, will be conducted by the NAASC. The NAASC will be responsible for ALMA within the NRAO program of education and public outreach (EPO).

The following organization chart shows the relationships of ALMA within the NRAO and to other entities involved in ALMA. It is consistent with the ALMA Project Plan (version of February, 2003) and with ALMA Operations Plan (version A) approved by the ALMA Board.

ALMA NSF AUI Board

Joint ALMA Observatory NRAO

NAASC GBT VLA & NTC VLBA

ALMA Board = NSF, AUI/NRAO, US astronomer, Canada, ESO, ESO Council President, European astronomer.

Figure 4.1. The relationships of the NAASC to ALMA and within the NRAO.

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The NAASC is organized into four units: Science, Technical Services, Business, and Data Management. One of these, Technical Services, is a sub‐activity of the NRAO Technology Center (NTC), supervised by the head of the NTC. The other units will be located in the expanded NRAO Edgemont Road building.

The ALMA Operations Plan refers to ALMA Regional Centers (ARCs), and the North American ARC is contained within the NAASC. The ARCs are responsible for so‐called core functions. The core functions provide activities necessary to receive and process observing proposals from and make accessible observational data to the user community. The other functions of the NAASC provide required infrastructure, enable and support the derivation of scientific results from ALMA data, foster the development of the user community, conduct a program of ALMA Fellows, and establish a program of ALMA education and public outreach for the United States.

The NAASC will serve the North American community. Canada will share in the support of and benefit from the NAASC in proportion to its share (7%) of the construction of ALMA compared with the United States. The only exceptions to this are data‐analysis grants to users and education and public outreach programs, where Canada will conduct its own programs. A major portion of the Canadian contribution to the NAASC is expected to be in kind; for example, repair of the electronics built in Canada, work on the archive, and development projects.

Figure 4.2. Staffing Plan for the NAASC. The NA ARC is shown in yellow.

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Description of NAASC Functions

The largest unit of the NAASC is the Data Management Division. The dominant role of data management in the NAASC is similar to the role that computing plays in the science support centers of the NASA astronomy missions, ESO’s Very Large Telescope, and user support groups of the other telescopes of the NRAO (whose future evolution is to be patterned on the NAASC). The success of ALMA depends critically on its software systems, and the NAASC is responsible for supporting the software that interfaces most directly with ALMA users, namely, software to submit and review proposals, construct observing programs, receive and distribute pipeline‐produced reference images, operate a data archive, analyze images, and organize communications with users via email and the internet. (The size of the data management task is indicated by the following: since its inception, the Hubble Space Telescope archive has grown to somewhat less than 20 Tbytes, whereas ALMA is expected to produce 100 Tbytes every year at current, perhaps low, estimates.) Of particular importance is the interface to the National Virtual Observatory (NVO). ALMA is to be completely “NVO compatible.” This requires efforts to establish and maintain the interface. Development of NVO software particular to radio astronomy is anticipated at the NAASC. The data‐management unit will have a team of twenty six: unit head, three in system administration to maintain the computing infrastructure of the Center, eleven programmers to maintain and improve software constructed by NA, five on the archive team [one database administrator and four technicians], and six software engineers to develop software for new ALMA capabilities.

The Deputy Head of the NAASC will lead the Science Division. Four scientists and two data analysts make up the staff to handle proposal functions, principally, helping users in using the Proposal Submission Tool (PST) to prepare and submit proposals, managing the refereeing and ranking of proposals, assisting in the construction and verification of observing scripts for proposals to be scheduled for observation, and ensuring that accepted proposals are properly characterized for pipeline processing of observational data. Four scientists make up the staff to support user science, principally, serving as the Astronomer on Duty at the ALMA Operations Support Facility (OSF) in Chile, providing quality assurance, giving assistance in the use of the archive, and assisting in off‐line data reduction.

The NAASC Technical Services Division is a subdivision of the NRAO Technology Center, headed by the head of the NTC. It is charged with the maintenance and repair of the hardware built by North America, and the development of new instrumentation. The total staffing required for these activities, based on experience during construction and in the NRAO Technology Center, is nineteen FTEs, including two co‐op engineering students.

The Science Development Division provides support and functionality beyond the ALMA core functions. The User Grants Program supports ALMA data analysis and publication by the U.S. user community, analogous to the NASA programs for HST, Spitzer, and Chandra. The

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Advance User Support staff of two astronomers and four programmers will provide many functions to enable NA ALMA users to fully exploit the telescopes capabilities. These include organizing workshops; providing full post‐observation users support (e.g. personal help with off‐line data reduction and re‐processing of large and/or complex datasets); providing improved cookbooks, data‐analysis documents, and reduction tools; supporting special projects (e.g. public surveys and large programs); developing new approaches/algorithms for calibration and imaging, advanced simulation development, and improved observing techniques. The ALMA Fellows Program (two Fellows per year for four‐year appointments) is similar to the Jansky Fellows Program for the rest of the NRAO, the Hubble Fellows Program of the Space Telescope Science Institute, and similar programs at other world‐class observatories. The ALMA Postdoctoral program (two Postdocs per year for three‐year appointments) will train young astronomers on the detailed operations of ALMA. The Professional Development program requires one astronomer to run student programs, organize schools, schedule talks, and maintain an ALMA presence at scientific meetings. It also provides support for two pre‐ doctoral students. The ALMA education and public outreach staff includes a public information officer, two public education officers, five public education assistants, and a Webmaster. Some of these positions might in time be funded by external contracts.

The AUI/NRAO Office of Chilean Affairs, although not, strictly speaking, part of the NAASC, performs corporate/observatory functions essential to the operation of ALMA in Chile. These functions include representation of AUI/NRAO to the government of Chile for ALMA, responsibility for ensuring that North America’s share of the business activities of ALMA in Chile are conducted according to the terms of the cooperative agreement between AUI and the NSF and any other regulations that may apply, and any other activity that requires the fiduciary presence of AUI in Chile for ALMA.

User Data‐Analysis Grants

The large investment in the construction of ALMA and the importance of the scientific questions to be addressed by ALMA make the interpretation of ALMA data products and their publication critically important to ALMA’s success. For these reasons we are convinced that a user‐support program for data reduction, interpretation, and publication should be established. Such programs are an essential component of NASA missions and were strongly endorsed by the last Decadal Report for Astronomy and Astrophysics for new NSF‐funded facilities. The ALMA North American Science Advisory Committee has been very supportive of establishing such a program, and the proposal to do so has been well received by the community in ALMA town meetings and workshops. Although it will be a number of years before such a program is needed, we will continue to study this aspect of the Hubble, Spitzer, and Chandra missions, discuss the requirements with the user community, and submit a formal request for the establishment of the program to the NSF at the appropriate time. We note that the program need not be operated by AUI/NRAO. It could be run by another institution or by the NSF itself.

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NAASC Activities in FY 2006

The NAASC tasks to be accomplished in FY 2006 continue the organization and planning of FY 2005 but have a growing emphasis on tasks such as software testing, community relations, and preparation of observing tools. There will be eight FTE positions supported by ALMA operations funds (identified in red in the NAASC Staffing Chart above) and several additional scientists supported by NRAO operations with functional duties in the NAASC. The following list is a summary of the principal tasks for FY 2006.

1. Completion of detailed plans for the NAASC that are consistent with an ALMA Operations Plan approved by the ALMA Board. The rough outlines of these plans are available today, but they require work to clearly define the interfaces between Chile operations and the ARCs, determine total requirements year by year to full operations, and, most importantly, establish the transition from construction to operations. We have and will continue to study the operations of the Hubble, Spitzer, and Chandra science centers and are in close contact with the team planning the Herschel science center.

2. Software testing. The emphasis in FY 2006 will be testing the proposal submission tool and pipeline data‐reduction system. These software tests are part of the regular schedule of tests organized by the ALMA Computing IPT. NAASC staff and other interested parties participate to provide external reviews of the software and to gain experience in its use.

3. Community Relations. The principal activity in this area is to keep the community informed on the status of the ALMA project, building interest while managing expectations. A town meeting will be held at the Washington, D.C. meeting of the AAS in January 2006, and a special session will be organized at the summer meeting of the AAS in Calgary. The program for this special session is being developed jointly with Canadian scientists. It will be held on the day that the AAS meets jointly with the Canadian Astronomical Society.

Several scientific workshops are being planned. Following the January 2006 AAS meeting, a workshop, “From z‐Machines to ALMA: (sub)Millimeter Spectroscopy of Galaxies” will be held at the NRAO in Charlottesville. A joint workshop with Herschel is planned for late spring 2007. Discussions are being organized for a joint workshop with the James Webb Space Telescope (JWST) project. The NAASC will have the North American responsibilities for the ALMA Science Symposium to be held in Madrid in the fall of 2006.

It is anticipated that the current series of summer schools on aperture‐synthesis radio astronomy held every two years at the NRAO in Socorro will be revised into a program that alternates between centimeter‐wavelength and millimeter‐wavelength aperture‐

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synthesis summer schools. The latter will start in Charlottesville and may move among a set of universities after that. The intention is to train observers in the aperture‐synthesis techniques used by ALMA, with attention to the peculiarities of millimeter wavelengths.

4. Database Construction. Databases of spectral‐line frequencies and phase‐ calibration sources are required. Work has begun on a spectral‐line frequency table for a large number of known and possible interstellar molecular species to aid observers in planning and interpreting their observations. The goal is to build the frequency table into the observing/proposal tool and to have it available on‐line for widespread and easy access by users. Work on this table and its web interface will continue in FY 2006, as will work on the list of calibration sources. Specifically, the Antenna Test Facility will be used to survey the portion of the northern sky accessible to ALMA for continuum sources that are strong at millimeter wavelengths.

5. Advanced Data‐Reduction Software. The ALMA construction project is supporting the development of AIPS++ only to the extent required for the production of data products. Software required for further reduction of ALMA data is an operational responsibility. In FY 2006 the NAASC activities will include support of four FTE programmers working on such software. The lead times for astronomical software are long, and we consider this activity to be essential to the success of ALMA as a scientifically productive and user‐ friendly facility.

6. Antenna Test Facility Support. NAASC staff will participate in observing runs (calibration‐source survey) and tests conducted at the ATF. This is essential to gain experience in the use of the real‐time software and reduction of ALMA data.

7. Education and Public Outreach. The ALMA component of the NRAO EPO program will concentrate on improving the website. In addition, work will continue on supporting an ALMA presence at scientific meetings, development of brochures and displays, and issuing press releases as appropriate.

ALMA Operations in Chile

The Joint ALMA Office is developing a complete program of activities for FY 2006. That program, to be submitted to the ALMA Board for approval, was not formally available at the submission time of this Program Plan. However, the dominant budget elements will be purchases of start‐up operations equipment and the hiring and training of the first key operations personnel, for example, the Head of Operations and Head of Administration, who will further develop the details of the ALMA Operations Plan.

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5. Expanded Very Large Array

Overview

The EVLA Phase I Project preserves the large existing investment in VLA antennas and civil infrastructure, and it adds new wideband receiver systems, a state‐of‐the‐art correlator, a fiber‐ optic data‐transmission system, digital electronics, and a new on‐line control system to yield a new instrument with the following improvements over the present VLA:

• Continuum sensitivity improvements from up to a factor of 5 for λ > 3 cm (< 10 GHz) to more than 20 between λ = 3 and 0.6 cm (10 and 50 GHz). • Operation at any wavelength from λ = 0.6 to 30 cm (1.0 to 50 GHz) yielding two pairs of signals, each pair with opposite polarizations and up to 4 GHz bandwidth, independently tunable to any frequency within any given band. • A flexible new correlator which will provide over 16,384 frequency channels, process the full EVLA bandwidths, and give frequency resolution better than 1 Hz if necessary.

The impact on astrophysics of making these improvements to the VLA will be profound. Many severe limitations now constraining VLA observations will be removed or greatly relaxed.

A short selection of unique scientific research made possible by EVLA I includes:

• Measuring the three‐dimensional structure of the magnetic field of the Sun. • Using the scattering of radio waves to map the changing structure of the dynamic heliosphere. • Measuring the rotation speeds of asteroids. • Observing ambipolar diffusion and thermal jet motions in young stellar objects. • Measuring three‐dimensional motions of ionized gas and stars in the center of the Galaxy. • Mapping the magnetic fields in individual galaxy clusters. • Conducting unbiased searches for redshifted atomic and molecular absorption lines. • Looking through the enshrouding dust to image the formation of high‐redshift galaxies. • Disentangling starburst from black hole activity in the early universe. • Providing direct size and expansion estimates for up to 100 gamma‐ray bursts every year. • Measuring the proper motions of a large sample of pulsars. • Imaging thermal objects such as a large sample of stars and novae with tens of milliarcsec resolution.

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The EVLA Phase II Project would increase the spatial resolution of the VLA by a factor of 10 by building eight telescopes around the VLA at distances up to 250 km. These telescopes, plus two VLBA telescopes, will be linked to the VLA using a leased network of fiber‐optic cable. Another part of the Phase II Project will be construction of an ultra‐compact E configuration at the VLA which will provide increased brightness sensitivity compared to the D configuration. A proposal for the Phase II Project was submitted to the NSF in April 2004 and a Reverse Site Visit for that proposal was held in June 2005. NRAO is waiting to hear from the NSF concerning funding possibilities for Phase II.

Phase I Progress

During FY 2005 the EVLA Phase I Project was in its fifth year of funding. Progress during the year will be discussed with respect to each of the nine goals established for the project in the 2005 Program Plan.

1. Completion of the outfitting of the second EVLA antenna. One IF set of electronics was installed in the second EVLA antenna (14) and the first interferometric fringes were obtained with both the VLA and the EVLA Test Antenna on December 2, 2004. This provided the first fringes between two EVLA antennas. Antenna 14 has become the primary EVLA Test Antenna with the core receivers (C, K, L, Q and X‐band) installed. Installation of modules for 4 IF operation is planned for August 2005.

2. Retrofit of the Test Antenna to full EVLA production design. The first EVLA Test Antenna, Antenna 13, was the early prototype antenna and it was withdrawn from service to upgrade its equipment to the final design in March 2005. The new electronic rack configuration has been installed and electronic modules will be installed for four IF operation at the end of FY 2005.

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Figure 5.1. EVLA equipment racks installed on the third EVLA antenna.

3. Outfitting of three additional antennas to EVLA design. Two additional antennas were outfitted to EVLA design rather than the goal of three antennas. The schedule delay was caused by the need to redesign a critical electronic module (Digital Transmission System), and the need to perform more detailed testing and debugging on the overall system. Antenna 16 was refitted as the third EVLA antenna and was placed into the array in spring 2005. With Antenna 14, it is now being used for routine testing. As the first production antenna, Antenna 16 was populated with the full complement of hardware to support operation with four IFs. Figure 5.1 shows the EVLA electronic equipment installed in Antenna 16. Antenna 18 was the fourth antenna to be refitted with EVLA equipment. The mechanical outfitting is complete, and electronics installation will occur in the fourth quarter of 2005.

4. Continued splicing of the fiber optic cables and termination of the fibers at the antenna pads. Fiber optic termination boxes have been set at all seventy two VLA array stations and thirty three out of seventy two have been spliced together. The goal of 75% achievement of this work has been exceeded. Currently there are sixteen array stations available for location of EVLA antennas.

5. Begin installation of the new wideband L, C and Ka‐band receivers on the EVLA antennas. The new wideband L and C‐band feeds were successfully tested on the antenna and are now in production and are being installed on EVLA antennas. Figure 5.2 shows the new EVLA feed package on an EVLA antenna. The new Ka‐band feed has

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been successfully tested on the antenna range. C‐band receivers are now being routinely installed on antennas. Installation of the first wideband L‐band receiver was delayed due to design difficulties with the wideband orthomode transducer but is now scheduled for completion in December 2005. In the meantime the project continues the use of the old narrow band L‐band receivers. The Ka‐band prototype is in the early stages of design. Two Downconverter Modules for the new Ka‐Band receiver have been assembled at Caltech. Completion of the Ka‐band prototype is expected in January 2006.

Figure 5.2. New EVLA wideband feed system installed on an EVLA antenna.

6. Commencement of routine observing with the EVLA antennas in “transition mode”. The use of EVLA antennas for routine VLA operation was delayed by the need to redesign the Digital Transmission System module and the debugging of Monitor and Control software, which supports GUI interfaces to the Observation Executor, alert status of antenna hardware, antenna checkout/acceptance, startup after maintenance day, and other tests. Training of VLA Operators in the operation of EVLA antennas has commenced and first use of EVLA antennas for observations is now scheduled for the last quarter of 2005.

7. Continue design and construction of the EVLA correlator. The Canadian Partners, the Herzberg Institute of Astrophysics, performed a Critical Design Review (CDR) for the correlator chip in January 2005, and the contract for chip fabrication was awarded. About 200 prototype correlator chips are expected for delivery in October 2005 for performance testing.

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A Preliminary Design Review of the entire correlator was held in July 2005. Designs are complete for the baseline board, where correlation is performed, and the station board, which prepares antenna signals for correlation by filtering and delaying the signals. A reliability analysis was conducted to estimate the number of spare boards required to support correlator maintenance.

The architecture of the correlator software system has been developed which includes implementation designs for the master correlator control computer, hardware and software interfaces, graphical user interfaces, and the correlator backend system.

Construction of the new RFI shielded chamber has proceeded ahead of schedule. The chamber, which will have an area of 2200 square feet, will be built in a large room in the VLA Control Building to the east of the VLA Control Room. The large room has been prepared and a contract has been awarded for the chamber, with installation scheduled to start in September 2005. Figure 5.3 shows the layout planned for the correlator.

Figure 5.3. Planned layout for the EVLA correlator.

8. Continued procurement of large production orders of critical components. Procurement of production quantities of components proceeded in most areas of the project. In a few areas testing showed that design changes were required and so production quantities will not be procured until later in the project. Examples of the large procurements

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placed during FY 2005 included:

• L and C‐band feed horn centrifugal cast aluminum parts • Machined metal parts for module assemblies • M&C pre‐assembled module interface boards • L‐band receiver 1‐2 GHz post amplifiers • Antenna 48 volt DC power supply converters • WIDAR correlator RFI shielded room and HVAC units • UX converter integrated circuit boards • Feed horn towers • Antenna RF cables and connectors • RFI shielded chamber

9. Procure components for, and begin construction of, the electronics systems required for the antennas to be outfitted in FY 2006. The project continued with procurement of the core components needed to keep pace with the construction and outfitting of antennas and testing of electronics modules due for service in early FY 2006.

Planned Activities for FY 2006

1. Outfitting of three additional antennas to EVLA design. Three more VLA antennas will be converted to EVLA design. Of these additional antennas, one will also receive a new azimuth bearing (funded from VLA operations budget). In most areas of the project, hardware production is well underway. The goal is to outfit the next three antennas with production hardware. This will bring the total number of EVLA antenna to seven by the end of FY 2006.

2. Use of EVLA antennas for routine VLA operation. As noted above, the goal of returning EVLA antennas to routine observing with the rest of the VLA antennas was not achieved in FY 2005. It is now planned that this goal will be achieved in FY 2006. This will require completion of testing and debugging of the hardware and control software and provision of some additional software to allow VLA Operators to control and monitor EVLA antennas. By the end of FY 2006 completed EVLA antennas should be in operation.

3. New correlator RFI shielded chamber complete. The large new RFI‐shielded chamber for the new correlator will be fully outfitted and available for use. RFI testing of the newly assembled shielded room will began in early fall 2005. The electrical and HVAC mechanical systems will all be installed and working by the end of FY 2006.

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4. Complete the array fiber infrastructure installation. By the end of FY 2006, all 72 array stations will be completely cabled with optical fibers for LO, IF, and Ethernet connect allowing EVLA antennas to be located anywhere on the array.

5. Continue design and construction of the EVLA correlator. The Canadian Partners will continue the prototype assembly and testing of the Baseline board and the Station board throughout the new fiscal year to achieve integration testing of prototype hardware and software by early fall 2006. Preparations to ship the prototype correlator will begin.

Working closely with NRAO engineers on the correlator room layout, construction, and power requirements, the correlator rack design and thermal testing will be completed and detailed drawings for the rack and rack components produced. The tendering and bidding process for fabrication of this hardware will occur. The goal is to provide rack hardware to be installed and fit tested in the completed RFI shielded room upon its completion.

6. Complete top‐level design of e2e software. In previous years, limited personnel resources have delayed progress on e2e software for the project. With the approval of two new software engineering positions from the project budget, significant work can resume. In FY 2006 the e2e top‐level architecture will be designed and agreements will be made with the ALMA Project concerning project model and science data model so that reuse of ALMA e2e software can be planned.

Planned Activities beyond FY 2006

The current rate of project funding, as approved by the National Science Board and modified by the one year of accelerated funding in FY 2004, will provide the last funds for the project in FY 2011.

Beyond FY 2006 the retrofitting of VLA antennas to the EVLA design will proceed at a rate of five antennas per year, with one antenna each year receiving a new azimuth bearing (funded from operations). This rate of antenna outfitting will complete the conversion of all antennas to EVLA design in the third quarter of 2010. The last EVLA receiver is scheduled for installation in early 2012.

The Canadian Partners are currently planning to perform tests of the prototype correlator at the VLA in the first quarter 2007 with the complete commissioning of the full correlator scheduled for the last quarter 2009.

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During the years 2007‐2011 the major elements of the e2e suite of programs are scheduled to progress through alpha and beta releases to a full release. The major e2e elements include proposal tool, observation preparation tool, scheduling tool, science archive, pipeline and observation status tool. Further detail on these plans can be found in Chapter 9, Observatory Software.

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6. NRAO Facilities

Green Bank Telescope

Figure 6.1. The Robert C. Byrd Green Bank Telescope.

The GBT is now in routine scientific operation at essentially all frequencies from 290 MHz to 48 GHz, (wavelengths from 1m to 6mm) with the Ka‐band receiver (26 ‐ 40GHz) commissioned in FY 2005. About 5760 hours of telescope time was scheduled for astronomy programs during the year, amounting to over 65% of the total time, based on 24‐hour per day observing. The remainder of the time went to commissioning of new capabilities, particularly for high‐ frequency instrumentation and development, and to scheduled maintenance. Starting in October 2005 maintenance time will be reduced to one flexibly scheduled eight hour maintenance day per week, with an over‐ride on another half‐day should critical activities arise. The time planned for astronomy in the first four months of FY 2006 (Semester 05C) is 2130 hours, or over 72% of the total available time.

The GBT has a complete suite of observing instrumentation available for regular use by observers. This includes ten receivers ranging in frequency from 290 MHz to 48 GHz. Several detector backends are available, including the 256k‐channel GBT Spectrometer, the older Spectral Processor, the Digital Continuum Receiver, and VLBA recorders. Several backends constructed by university groups are also installed at the GBT for pulsar and bi‐static radar observing. These include the Berkeley‐Caltech Pulsar Machine (BCPM), the Caltech‐Green Bank‐Swinburne Recorder II (CGSR2), the Green Bank Astronomical Signal Processor (GASP)

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constructed by U.C. Berkeley and U. British Columbia, and the Cornell‐JPL Fast Sampler for bi‐ static radar observations. Use of the Pulsar Spigot Mode of the Spectrometer is now routine, and continues to be a great success. New instrument development in FY 2005 included the completion and commissioning of the first two channels of the Ka‐band (26‐40 GHz) pseudo‐ correlation receiver, and completion of the Caltech Continuum Backend, which will be commissioned in winter 2005/06. Telescope performance continues to improve; a series of “out‐ of‐focus” holography measurements made in spring 2005 have allowed us to achieve an rms surface accuracy of ~ 320μm under benign night‐time conditions, again improving the performance delivered at Q‐band (48 GHz, 6mm).

The GBT has several key instrumental assets that give it unique scientific capabilities. Although the GBT has a breadth of useful capabilities, the strategic plan seeks to optimize performance in the unique areas described below.

High‐fidelity Imaging

The unblocked aperture of the GBT significantly reduces its sidelobes, producing an exceptionally clean main beam. At the frequency of the HI line, for example, the first sidelobes of the GBT are ~30 dB below peak response, compared to the ~20 dB typical of symmetric antennas with blockage. In addition, the GBT’s active surface reduces the aberrations and misalignments which produce coma and astigmatism compromising observations at high frequencies. The high‐quality optics of the GBT is one of its unique and powerful assets and represents a major step forward in capabilities.

Comparatively high angular resolution with sensitivity to total emitted flux and extended emission

The 100‐m aperture of the GBT affords the comparatively high angular resolution of 740[arcsec]/ν[GHz]. Thus, at 100 GHz the GBT resolution is ~7ʺ. Furthermore, as a single dish, the GBT is sensitive to total flux from all angular scales. This is a key difference from interferometers, which can provide very high resolution but may be insensitive to extended emission. Sensitivity to total flux is a powerful asset for stand‐alone science, and is also extremely powerful when data from a single dish and a synthesis array such as the VLA are combined to produce an image rich in the details of the radio source at all angular scales.

Wide field of view

The Gregorian optics of the GBT afford a wide field of view that is relatively free of aberrations. At 3 mm wavelength, the useable field of view is about 10 arcmin and could contain up to 10,000 beams or pixels in a fully sampled array. The focal plane can thus accommodate large‐ format imaging cameras. When coupled with the high fidelity, the comparatively high angular

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resolution, and the sensitivity to extended, low‐brightness emission, it is evident that the GBT has unique potential as an imaging instrument. This is clearly a capability that we wish to foster through instrumentation and software initiatives.

High point‐source gain at frequencies from 300 MHz to 115 GHz

The GBT has a physical collecting area of 7854 m2. This aperture, the unblocked optics design, the active surface, and precision control system combine to provide extraordinary gain and point‐source sensitivity from low frequencies to, ultimately, 115 GHz. This gives the GBT high sensitivity to point sources such as pulsars, stars, and external galaxies. Because the GBT has high gain over three decades of frequency, it can be used to study cosmic phenomena that occur, or vary in nature, over a range of frequencies. For example, redshifted CO line emission may have lines that fall throughout the frequency range of the GBT, depending on the rotational transition and the redshift. A particularly valuable asset is the sensitivity of the GBT in the 26‐ 40 GHz range, to which J=1→0 CO lines are shifted for the supposed peak of star formation in the universe at z ~ 2.5. Extragalactic continuum sources may emit in thermal free‐free, synchrotron, or dust emission over ranges accessible to the GBT, which might then be used to separate the contributions of these phenomena to the continuum spectrum.

Comparatively low RFI contamination

The GBT is located in the National Radio Quiet Zone, a unique, national resource. Although Green Bank certainly experiences RFI, the natural topography of the area around the site in combination with Quiet Zone regulations continue to make it one of the best locations for radio astronomy in the world. For example, observations near the 1420 MHz HI line are largely free of contamination in Green Bank, whereas in certain parts of the world they have become almost impossible to carry out. We can exploit the Quiet Zone for numerous low‐frequency projects and will continue to protect it vigorously.

As is evident from the description above, the information present in the focal plane of the GBT is extensive and unique in both the spatial and frequency domains. In overview, the strategic plan for the GBT is to develop the scientific capabilities to capture this information as completely as possible. The specific strategic objectives and projects or programs that address them are listed in the table below.

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Table 6.1 GBT Strategic Objectives Strategic Objective Projects Addressing It Status Develop the high‐frequency ¾ Precision Telescope Control System In progress capability and performance of ¾ 3 mm (68‐92 GHz) Receiver In progress the GBT to 115 GHz. ¾ Ka‐band (26‐40 GHz) Receiver Commissioned ¾ Penn Array Bolometer Camera In progress ¾ Caltech Continuum Backends Commissioning Develop imaging cameras with ¾ Penn Array Bolometer Camera In progress increasingly large pixel formats ¾ Beam Forming Array Future at key bands, including 21 cm, ¾ 3 mm MMIC Array Future 1.3 cm, 1 cm, and 3 mm. ¾ 3CAM large format bolometer camera Future Develop ultra‐wideband ¾ Wideband Spectrometer In progress frequency analyzers for redshift searches Mitigate the effects of RFI, ¾ Interference Protection Work In progress enhance the available spectrum ¾ Quiet Zone administration In progress in Green Bank, and increase ¾ MRI Grant Project In progress, and protection in the National Radio recently renewed. Quiet Zone. Develop observing strategies ¾ Dynamic and Queue‐based scheduling In progress such as dynamic and queue‐ development. based scheduling that will allow observing programs to take best advantage of the prevailing weather and RFI environment. Work to sustain and enhance the ¾ Student Financial Support Program In progress single‐dish radio astronomy user ¾ University‐built Instrumentation In progress community through NRAO Program sponsored programs ¾ Single‐Dish summer School Held every two years Ease of use by both expert and ¾ Improved observation control facilities In progress non‐expert astronomers ¾ Improved data analysis facilities In progress

GBT Science Highlights in FY 2005

A sampling of the many significant GBT scientific results that were reported in FY 2005 follows below. This sample covers a wide range of research topics and demonstrates the power and versatility of the GBT, with experiments ranging from observing comets and tracking satellites in our solar system, to measurements of active galactic nuclei at redshifts > 0.5.

Comet 9P/Tempel

The GBT was used to detect the OH molecule in comet 9P/Tempe1 in the days immediately following its encounter with the probe of the Deep Impact spacecraft. The OH molecule in comets is produced by disassociation of H2O released from the comet’s surface. Surprisingly,

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the impact released considerably lower amounts of volatile gases into the coma than were expected, and in the first week after impact, the GBT alone had the sensitivity to detect the radio lines of OH.

Emission from OH was detected throughout eight days of observation of the comet, showing that some of the gas was likely emitted from the comet naturally, and was unrelated to the collision with the spacecraft probe. The lines varied in strength due to variation in gas production and the solar UV excitation of the OH molecules. Analysis of the kinematics of the lines may yield information on outflow velocities and rotation of the nucleus.

The Huygens Probe

On January 14, 2005 the Green Bank Telescope participated in experiments surrounding the Huygens Probe’s descent through the atmosphere of Titan, the largest of Saturn’s moons. The GBT acted as one element of a VLBI array eavesdropping on Huygens’ communications through a sidelobe of the Huygens telemetry antenna. The experiment was to determine the precise angular position of the probe as it dropped through the atmosphere of Titan, buffeted by its winds. In fact, the GBT was the first instrument to detect a signal from the probe, indicating that its descent had begun successfully. From the data scientists hope to measure the probe’s velocity during its descent, and thus a glimpse of the weather on Titan that day.

Detections of new pulsars in Terzan 5

Two dozen new pulsars have been detected in the globular cluster Terzan 5 using the Green Bank Telescope. Terzan 5 is a dense, massive globular cluster located near the center of our Galaxy. Previous searches had detected three pulsars in it, but the GBT observations were made at the relatively high frequency of 2 GHz to minimize pulse broadening by scatter and dispersion, and resulted in an observation that was about an order of magnitude more sensitive than previous searches. About half of the new pulsars are in binary systems, and several of these are of considerable interest. Two are in compact but highly eccentric orbits around likely white‐dwarf companions. Measurement of the precessions of periastron for both systems implies that at least one of the pulsars is significantly more massive than any other measured to date. Such a mass limits the equation of state for matter at nuclear densities. Ongoing observations will give information on dynamical conditions in the cluster core and information on the formation and evolution of pulsar binaries.

Observations of the Double Binary Pulsar J0737‐3039

The pulsar‐pulsar binary system J0737‐3039 continues to yield new fundamental measurements of General Relativity. As a result of sensitive GBT timing observations, the decay of the orbit due to gravitational‐wave damping has been detected: the binary orbit is shrinking by 7

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mm/day because of gravitational‐wave emission. The GBT observations have also led to detection of systematic pulse‐shape changes in the brighter pulsar of the pair, as expected due to geodetic precession predicted by General Relativity. The Shapiro delay parameter in this system is measured to be within 0.1 percent of the predicted value, the most stringent test of General Relativity in the strong‐field limit made so far. In a few more years of monitoring with the GBT additional effects should be measurable, including the pulsars’ spin‐orbit coupling, which should allow determination of the moment of inertia of a neutron star for the first time.

Cold Sugar

The GBT was used to perform studies of the biologically‐significant, interstellar molecule glycolaldehyde, the simplest member of the family of aldehyde sugars. Observations made toward the Galactic Center source Sgr B2N at 1‐2 cm wavelengths revealed spectral features showing absorption as well as emission. Analysis of the data indicated that a very cold (8 Kelvin) repository of glycolaldehyde was present. Earlier observations at 3 mm wavelength had found an extended cloud at 50 K temperature toward this source. These multi‐temperature regions are consistent with shocked environments, and suggest that glycolaldehyde is formed by the disruption of grain mantles caused by the passage of shock waves.

Water vapor masers from active galactic nuclei

Water vapor masers from active galactic nuclei can arise in a molecular disk viewed edge‐on, where conditions are favorable for their formation. The dynamics of these masers provide information on the central black hole and, if the disk can be imaged, give a direct geometrical distance to the masers. The GBT recently detected H2O maser emission from a quasar at a redshift z=0.66, ten times more distant than any previously known H2O maser. Its total luminosity makes it also the most powerful known. This object is located at a cosmologically interesting distance, where the apparent universal cosmological acceleration should be detectable. It may be the first of a set of H2O masers which will allow alternate measurements of this phenomenon.

GBT Accomplishments in FY 2005

Observing Software

To enable dynamic scheduling and remote observing, GBT software systems have been significantly re‐architected over the past two years. In FY 2005, these efforts culminated in the release of an observing application (ASTRID) and a data analysis application (GBTIDL).

ASTRID (the ASTRonomerʹs Integrated Desktop) is a unified workspace that incorporates the GBT’s new scheduling block‐based observing system with the real‐time quick look display. By

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encapsulating all of the underlying software systems that control the telescope, the observer is only required to learn one simplified system to observe on the GBT, rather than multiple applications as required in the past. ASTRID seamlessly combines telescope configuration and antenna movement, and allows observers to build observing scripts as part of their scheduling blocks well in advance of their observations.

Data Analysis Software

Significant strides are also being made in the arena of single dish data analysis. The platform for exploring data model issues has been the IDL product from Research Systems Inc. (RSI). An outcome of this process is a collection of interactive data reduction modules to support GBT observers while development on the long‐term pipeline processing solution takes place. These modules were released on schedule on May 31, 2005, with GBTIDL v1.0, which was updated with the release of GBTIDL v1.1 on July 6, 2005.

Heterodyne Instrumentation Program

Q‐band Receiver. The Q‐band (40‐52 GHz) receiver was significantly modified in summer 2004 to improve the calibration stability and reduce variations in bandpass shape as the LO frequency changes. The receiver was re‐commissioned in winter 2004/2005, made some excellent science observations, and was used with great effect to perform “out‐of‐focus” holography to improve the antenna performance. While the modifications were extremely effective at improving the baseline performance, they had the unfortunate side‐effect of reducing the usable bandwidth of the receiver to ~ 42 to 48 GHz.

Ka‐band Receiver. This receiver covers the 26‐40 GHz (1 cm wavelength) range. It is a dual‐ beam, dual–polarization receiver with pseudo‐correlation (continuous comparison) architecture. This architecture allows very fast switching between the two beams and effectively removes 1/f noise in broadband continuum measurements. This receiver covers the frequency range at which the 1 → 0 CO (115 GHz rest frequency) line will be shifted for galaxies at z ~ 2.5, which is believed to be the redshift of the peak of star formation in the universe. The GBT has high sensitivity and works extremely well in this frequency range. The first two spectral channels of this receiver were completed and commissioned in FY 2005, and some initial science observations were performed in spring 2005.

Caltech Continuum Backend (CCB). The CCB is a collaborative project between Caltech and NRAO to develop a fast‐switching high‐sensitivity continuum backend for use with the Ka‐ band and future W‐band (3 mm) receivers. The backend is capable of analyzing essentially the full bandwidths of each receiver, with the bands broken into three or four sub‐bands to allow some spectral analysis. The initial scientific driver for this instrument is to allow sensitive detection of weak radio sources so that cosmic background fields can be corrected for point‐

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source contamination. This will allow more accurate analysis of data from the Cosmic Background Imager and other anisotropy projects. In the longer term, this backend will facilitate sensitive observations of a variety of continuum sources in the 1cm and 3mm bands. The CCB was funded as part of the Observatory’s University‐built Instrumentation Program. Caltech and NRAO have collaborated closely on this instrument and both institutions have undertaken significant work packages as part of the project.

W‐band Receiver. The W‐band (68‐92 GHz) receiver is also a dual‐beam, dual‐polarization receiver with a similar architecture to the Ka‐band receiver. Construction of this receiver recommenced in FY 2005.

Wideband Spectrometer (Zpectometer). A natural GBT scientific target is the detection of very high‐redshift molecular line emission from the earliest galaxies. As noted, the supposed peak of star formation in the universe at z ~ 2.5 places the 1 → 0 CO line in the 26‐40 GHz Ka‐band region, where the GBT is uniquely sensitive. Higher‐lying CO lines will sample higher redshifts, and the 3 mm window will eventually be available for sampling yet more lines and redshifts. Figure 6.2 shows the accessibility of important CO and CI lines at a range of redshifts using GBT receivers.

Figure 6.2. CO and CI sky frequencies as a function of redshift, with overlays of GBT receiver coverage.

Since photometric redshifts have large uncertainties, a very wide‐bandwidth spectrometer that can simultaneously sample a range of redshifts would be an extremely powerful and

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scientifically valuable instrument. In FY 2005, Professor A. Harris of the University of Maryland received an ATI Grant to construct such a spectrometer for the GBT, based on his existing wideband spectrometer (WASP2) already in successful use at the Caltech Submillimeter Telescope. The NRAO is a co‐investigator on the proposal.

Penn Array Camera

The Penn Array is a 64‐pixel bolometer camera for the 3 mm band that is being developed by a consortium of the University of Pennsylvania, NASA‐Goddard, National Institute of Standards and Technology, Cardiff University, and NRAO. This project is also being funded largely through the NRAO University‐built Instrumentation Program. As noted in the discussion in the following strategic development section, the GBT has great scientific potential in both the imaging and millimeter‐wave science areas. The Penn Array will be the GBT’s first major instrument to combine both of these assets. The Penn Array should serve as a pathfinder toward much larger format arrays, but is an ambitious and extremely powerful scientific instrument in its own right. The camera has an 8x8‐pixel array with full spatial sampling, i.e., it will not be necessary to step the position of the telescope to achieve Nyquist sampling within the field‐of‐view of the array, which is approximately 30”x30”. The angular resolution will be about 8” per pixel. The detector array is made up of state‐of‐the‐art Transition Edge Sensors (TES’s) with SQUID multiplexers, all cooled to a cryogenic temperature of 0.25 K. The sensitivity of the array should be better than 500 µJy/√sec per pixel. This extraordinary sensitivity will open a number of areas of investigation, including observations of the Sunyaev‐ Zeldovich Effect, detection of galaxies with extremely high redshifts, and observations of trans‐ Neptunian and other weak solar‐system objects.

Construction of the receiver has made good progress in FY 2005. A prototype (1x4) detector array with lightly passivated bismuth absorber was produced at Goddard Space Flight Center. Two SQUID MUX columns were installed in the dewar and successfully tuned and operated, with test data acquired to disk. Configuration and readout of the MUX was accomplished fully under computer control, this is the first time this has been done with the NIST MkIII SQUID MUX. Several new versions of the firmware were produced, and much was learned about SQUID MUX operations. A complete RFI check and test installation in the GBT receiver cabin were successfully performed in August. Software has been written to interface the Penn Array DAQ software (IRC) with the GBT YGOR control system, and archive data to disk in FITS format.

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Precision Telescope Control System

Considerable progress was made on the Precision Telescope Control System (PTCS) Project in FY 2005. Updates to the pointing models developed in FY 2004, including gravitational and thermal coefficients and residual lookup‐tables, were released in November, and have been working extremely well since then. Significant upgrades have been made to the GBT real‐time display to allow processing of data taken with all switching schemes, including the new Ka‐ band receiver, and options added to allow less stringent and user defined heuristics for the assessment of the validity of peak and focus scans. Q‐band observers have reported excellent stability of both pointing and focus under benign night‐time conditions.

A number of advances were made on instrumentation work. The Quadrant Detector was significantly re‐engineered for improved performance. Under good conditions (low air turbulence) it now provides measurements of the position of the tip of the feed‐arm with respect to the elevation axle with an accuracy corresponding to ~0.2” of beam motion on the sky, after a linear‐detrend. We are using this device to assist in the characterization of the antenna tracking performance, both during the acquisition of out‐of‐focus beam maps, and in anticipation of the arrival of the Penn Array.

A pair of precision inclinometers have now been mounted on each elevation axle. These have been used to investigate azimuth track tilts, by rotating the antenna and making static measurements around the track at locations avoiding wheel/joint interactions. The measured data have been modeled including the zero‐points and temperature coefficients of the inclinometers, the track tilt terms, and terms proportional to the square of the alidade‐relative wind speed. The measurement uncertainty is less than 1”, and bootstrap estimates of the uncertainties of the tilt coefficients are ~0.2”.

Considerable work was performed on the next generation laser rangefinders. The new rangefinder is frequency diverse (100‐300 MHz), allowing absolute range measurements. It uses fiber‐optically coupled optics, which provide many advantages, including MEMS chopping, a fiber reference loop, and the ability to run many remote heads from a single electro‐optics package. The diverged optics mitigates pointing problems and small‐scale turbulence; the fiber‐ coupled optics could be mounted on the existing pointing heads. The new system has already demonstrated ~20μm performance on a 20m path. We now have a notional system design for a fixed surveying network on the GBT that can plausibly achieve the requisite pointing performance for 3 mm operations. This would use inclinometers mounted above the azimuth encoder to provide an absolute reference to local gravity, and fixed‐range range and angle‐angle measurements to relay this co‐ordinate frame to each end of the elevation axle in the first instance. The design has a variety of good properties, e.g., all weather operation. This approach would allow us to compensate pointing for effects in the alidade, including wind and azimuth track irregularities.

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In spring 2005, we performed out‐of‐focus (OOF) maps on 3C84, 3C279, 3C286, and 3C345 over a range of elevations and thermal conditions. These observations were made at Q‐band (43GHz, 7mm), using look‐up table corrections for the active surface derived from earlier data obtained in March. Application of the large‐scale OOF corrections makes a significant improvement to the aperture efficiency, ranging from ~10% (benign night‐time conditions at the rigging angle) to ~60% (low elevation and/or daytime). Absolute efficiency measurements are complex, and the analysis is still underway. However, preliminary results suggest a peak Q‐ band efficiency after large‐scale corrections of ~0.51, yielding a surface accuracy of ~320μm. Not surprisingly, one of the main aberrations during the daytime appears to be astigmatism due to displacement of the subreflector. We hope to use the radial focus and elevation pointing corrections (either as predicted from the dynamic corrections system, or as measured) to determine and correct for this effect. This should allow us to correct for the bulk of the daytime mis‐collimation without the need for a real‐time OOF measurement. At the same time we expect to have the OOF measurement and analysis process completely automated by fall 2005, so that a full round of measurement and adjustment can be made in ~ 20 minutes.

As part of the efforts to understand Ka‐band and Q‐band efficiency measurements, we have started investigating the performance of the antenna servo in more detail. During “nodded” efficiency observations, it is clear that the servo performance when slewing to the positive beam is significantly better than slewing to the negative beam. This appears especially obvious when the azimuth component of the sidereal velocity of the source cancels the azimuth motion required to reach the other beam, leaving a net azimuth velocity demand of ~ zero. The poor servo performance under these conditions is assumed to be due to static friction on the azimuth drive wheels; this potential problem was noted in early GBT memos. A similar effect may explain the poor servo performance when performing “daisy‐petal” and other continuous raster scans; the worst performance again occurring when the net azimuth velocity demand crosses zero. Techniques to ameliorate the impact of this effect on observing are being investigated. At the same time, we have begun a low‐level investigation into other antenna control related issues, particularly problems with antenna trajectory calculations. We are being assisted in this area by Fred Schwab and Rick Fisher in Charlottesville.

Azimuth Track Refurbishment

We continue to successfully mitigate the impact of the azimuth track deterioration on operations via a carefully managed program of ongoing maintenance. The track joint modified in FY 2003 continues to perform well, as do two trial plates made of American Iron and Steel Institute (AISI) 4340 material which were installed in FY 2004.

The NRAO engineering staff, together with external engineering firms, has conducted an extensive program of modeling, metallurgical analysis, and specific measurements of stress and pressure over the past two years. These studies have found that the material type, material

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thickness, fastening design, and joint design should be retrofitted to provide a long‐lived, more easily maintained track.

Based on these studies, designs for the retrofit of the track are now complete. These were reviewed by an external panel in December 2004, with modifications resulting from the comments of the panel incorporated in spring 2005. The new design incorporates new base plates of stronger grade steel, and wider and thicker wear plates of more fatigue‐resistant steel. A final panel review is scheduled for August 2005, and contracts will be let soon after.

Non‐Programmatic Funded Projects

In addition to our main GBT development work, Green Bank staff worked on a number of projects during FY 2005 that were funded from sources other than NSF‐AST. The most significant of these, the 43m MIT/Lincoln Labs project and work on the Solar Radio Burst Spectrometer, have been done on a full cost‐recovery basis, and so as well as enabling the relevant science, have provided some alternative funding during a tight budget year. In the case of the 43m project, this work will result in a refurbished telescope. In other cases, such as the Precision Array to Probe the Epoch of Reionization (PAPER), relatively modest NRAO contributions have significantly assisted university instrumentation groups, as well as providing them access to the unique National Radio Quiet Zone.

43m MIT/Lincoln Labs Project

In FY 2005, NRAO and Lincoln Laboratories entered into a collaborative agreement to measure the properties of the Earthʹs ionosphere using bi‐static radar techniques. The program will consist of two phases: (I) System Development and Implementation, and (II) Operations. Phase I is expected to be completed in FY 2005 and be followed by a minimum of one year and a maximum of five years of operations. Lincoln Laboratories is building a special wide‐band (150 to 1700 MHz) feed and front end system that will be installed on the NRAO 43m (140ft) telescope. The NRAO is developing an automated system to follow Lincoln Laboratory’s spacecraft coordinates. The 43m will track satellite beacons and also spacecraft illuminated by the Millstone Radar at Haystack Massachusetts. Lincoln Laboratoryʹs engineers will drive a semi‐trailer full of high speed electronics to Green Bank, where it will be installed at the base of the 43m telescope. The trailer is shielded to contain any radio frequency interference the electronics may generate. The Lincoln Laboratory’s electronics will select and sample the RF signals and write the digital data to a disk recording system. The disk packs will be mailed to the Lincoln Laboratories office in Lexington Massachusetts for further analysis.

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Previous 43m operations were halted in 1999, and one of the first tasks for NRAO was to demonstrate that we could fully restore the 43m to operation. Detailed tests of the hydraulics system were required before the collaboration could begin. The 43m hydraulic systems have now been restored to full operations, and a new control computer system has been installed.

Interference Countermeasures (MRI Project)

The Observatory’s RFI mitigation program works at several levels. Within Green Bank Operations, the Interference Protection Group seeks out and mitigates sources of RFI in equipment, utilities, etc., both on site and in the vicinity of the observatory. We aggressively administer the National Radio Quiet Zone to preserve the unique protection it affords. Despite these efforts at RFI containment, there are still significant sources of RFI arising from ground‐ based transmitters outside the Quiet Zone, from aircraft, and from satellites. A strategic development program to mitigate these sources of RFI has been funded through NSF grants to NRAO and Brigham Young University. These grants were renewed in the past year and will focus on transferring proven RFI excision algorithms to real‐time hardware for the benefit of routine astronomical observing. These algorithms remove pulsed signals emitted by ground‐ based radar and airborne distance‐measuring equipment, and they remove continuously transmitted signals from aircraft and terrestrial sources using adaptive‐canceling techniques. The work done as part of this project is of great benefit to the field of radio astronomy in addition to specific benefits to GBT observations.

Solar Radio Burst Spectrometer

The Green Bank Solar Radio Burst Spectrometer (SRBS) is a collaboration between Richard Bradley (NRAO) and the University of Maryland. Green Bank staff have assisted this project with the construction of a new servo system for the telescope, as well as support for getting the antenna running under control of software used for the OVLBI project.

Precision Array to Probe the Epoch of Reionization

D. Backer (UC‐Berkeley) and R. Bradley (NRAO) are developing a 32‐element array to be deployed on the Green Bank site for the next phase of prototyping their Precision Array to Probe the Epoch of Reionization (PAPER). They are exploring continuing and expanding the experiment in Western Australia, or another low‐RFI site, in FY 2006 if sufficient funding is obtained. The externally provided components of the PAPER‐32 array may be provided to the Frequency‐Agile Solar Array (FASR) design and development team which would allow them to conduct pre‐FASR imaging experiments. In addition PAPER‐32 may be used for: solar flare imaging as part of the SRBS, graduate instrumentation education, and public outreach. In FY 2005, we provided modest assistance to the PAPER team to construct and deploy the initial antenna elements, and provided infrastructural support to the project.

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GBT Plans for FY 2006

Observing Software

As of summer 2005, ASTRID supported most types of GBT observations, with the exception of non‐sidereal sources (e.g. solar system ephemerides) and the data taking control of the pulsar spigot. This remaining functionality, along with a real‐time status display, is scheduled for development and release in the fall 2005. Visiting observers started to transition to ASTRID in July 2005; this transition process will be complete by the end of the year, i.e., early in FY 2006.

Work on this system drew heavily from ALMA Observing Tool specifications, and focused solely on the execution process for a single Scheduling Block; the remaining task, however, is to implement a solution to manage multiple Scheduling Blocks in the context of an observer’s Science Program. This is best done by adopting and integrating an existing software solution, such as the one used by the JCMT or the one being developed for ALMA.

The primary challenge remaining is to find the most effective balance between Scheduling Block based observing and interactive observing, which many astronomers feel is crucial to optimizing the flexibility of the instrument. We are confident that our solution, using ASTRID, will provide the best features of each approach. A secondary challenge lies in transferring this technology to visiting observers, which requires careful adaptation of observing policies and procedures. Work on these two issues began in summer 2005 and will continue until streamlined practices for flexible scheduling are in place. By 2006, management of Scheduling Blocks in the context of Science Programs will be implemented, ideally by the adoption and adaptation of an existing software solution. To facilitate effective, efficient operation, all observations will be performed using Scheduling Blocks and ASTRID.

Data Analysis Software

In fall 2005, the IDL algorithms are being retrofitted into the quick look data display. Upon completion, GBT data for all continuum and spectral line observing modes will be displayed in real‐time by one software application for the first time. The system is also being made to display spectra integration by integration, which is a new capability for production GBT software.

At this point, GBT will begin its transition to longer‐term issues by working on flagging, calibration and imaging. A generic flagging solution will be developed with the long‐term (i.e. non‐IDL) data analysis solution in mind, but will be tested and refined by integrating it into the GBTIDL package. A new activity is being launched to refine calibration approaches and software for all standard GBT observing modes. Imaging work, currently being done by members of the scientific staff, will be integrated into production software and maintenance will

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be handled by software staff. When all of these are complete, a long‐term design study to determine best ways to support pipeline processing (which will be required when the Penn Array enters common user mode) will be initiated.

The main challenge in FY 2006 related to data analysis work will be transitioning from a focus on satisfying the needs of current GBT observers, to accommodating the data analysis needs of future observers using new instrumentation. We will continue supporting the GBTIDL data analysis package as a platform for collaborating with visiting observers, and as a rapid development environment for data analysis for new instrumentation. The Science Data Model (SDM), which has been under investigation as part of GBTIDL work since 2004, will be finalized in FY 2006 to optimize GBT’s ability to use and derive data analysis code from external sources including ALMA. Specifications for flagging and calibration for all GBT standard observing modes will be finalized, and flagging capabilities will be added to the GBTIDL package. A calibration service which can be used interoperably by GBTIDL and other software will be developed to ensure continuity of calibration approaches across applications. The GBT SDM will be augmented with this additional information and formally documented. Quality assurance methods will continue to be pursued. Methods and best practices for continuum and spectral line imaging will be compiled, leveraging the work of scientists across NRAO and other analysis packages such as AIPS and AIPS++. To jointly support dynamic scheduling work, and to lay the foundations for pipeline processing which will be required in FY 2009 and beyond, a means to accurately and concisely characterize observer intent will also be defined.

Heterodyne Instrument Program

Q‐band Receiver. Given the extreme pressure on high‐frequency commissioning time in FY 2006, we made the decision not to make further modifications to the receiver in FY 2005, but retrofits to restore the full bandwidth of the receiver will be made in summer 2006.

Ka‐band Receiver. Over the summer 2005, we completed the remaining two channels and improved the LO distribution system. The Ka‐band receiver will be available for production astronomy starting winter 2005/2006.

Caltech Continuum Backend (CCB). The CCB is nearing completion and is scheduled for commissioning starting December 2005.

W‐band Receiver. The W‐band receiver is expected to be completed in FY 2006. Unfortunately, lack of support scientist effort means that this receiver is unlikely to be commissioned on the telescope in FY 2006.

Wideband Spectrometer (Zpectometer). This instrument will be constructed over two years, starting in FY 2006, and will be a major scientific addition to the GBT.

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Penn Array Camera

We expect the Goddard Space Flight Center detector recipe will be suitable for an 8x8 engineering array that is planned to be used in winter 2005/2006 for GBT “first light” tests; initial engineering commissioning will commence in February 2006.

Precision Telescope Control System

Unfortunately, it became clear during FY 2005 that our existing Precision Telescope Control System (PTCS) project plan was too ambitious. The main issues were lack of software and scientific effort to support the main electronics development. The project was dealt another blow in spring 2005 by the resignation of the PTCS Systems Engineer. In light of these realities, we have scaled back the work currently being performed on PTCS, but plan to recommence a more focused and staged approach in FY 2006, as described in the next section.

Azimuth Track Refurbishment

Due to the long lead time on obtaining the materials, the construction work for the Azimuth Track Refurbishment will occur in summer 2007.

Non‐programmatic Funded Projects

43m MIT/Lincoln Labs Project

We expect to install the Lincoln Laboratories feed and front end system in September 2005 and make the first test observations in October 2005; this will be the first year of the operations phase of the project.

Interference Countermeasures (MRI Project)

The work done as part of this project is of great benefit to the field of radio astronomy in addition to specific benefits to GBT observations. Research on new techniques will continue.

Solar Radio Burst Spectrometer

This work will continue in FY 2006. Additional details are provided in Chapter 7.

Precision Array to Probe the Epoch of Reionization

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In FY 2005, we provided modest assistance to the PAPER team to construct and deploy the initial antenna elements, and provided infrastructural support to the project. We expect this work to continue at a similar level in FY 2006.

GBT Deliverables in FY 2006 and Beyond

The key GBT operational objectives for FY 2006 are as follows:

• To provide effective, efficient observing at all frequencies up to and including Q‐band (~52GHz / ~6mm). • To commence 3mm operation with initial engineering tests of the Penn Array. • To continue the azimuth track refurbishment program, putting all plans in place for a summer 2007 engineering shutdown and track repair period. • Production Q‐band science at 42 ‐ 48 GHz in the winter of 2005/06, with restoration of the full 40 ‐ 52 GHz bandwidth in summer 2006. • Ka‐band spectral‐line re‐commissioning and production science use. • Completion, commissioning and production use of the Caltech Continuum Backend. • Excellent science observations at K‐band and below. • Integration of the pulsar spigot control into the standard observing system. • Investigation into the possibility of a dual frequency (300/800 MHz) prime focus feed.

We will continue to extend our current “manual” dynamic scheduling policies and processes, to enable more effective use of high frequency observing conditions, and to prototype new approaches in preparation for winter 2006/07.

In addition to our main GBT program, we will continue so support the MIT/Lincoln labs 43m and SRBS projects described above.

Table 6.2 summarizes GBT deliverables for FY 2006 and subsequent years. It should be noted that the milestones in FY 2007 and beyond are somewhat uncertain, and critically dependent on funding profiles.

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Table 6.2. GBT Milestones with Baseline Budget Item Delivery Date Initiate 43m MIT/LL test observations 10/2005 Q‐band production science begins 10/2005 Initiate Zpectrometer instrument construction 11/2005 Ka‐band spectral line commissioning complete 11/2005 Begin CCB commissioning 12/2005 Integrate pulsar spigot control into std observing 12/2005 AZ track refurbishment contracts let 12/2005 Initiate Penn Array / 3mm engineering tests 02/2006 Agree dynamic scheduling policies and processes 05/2006 Finalize GBT Science Data Model 09/2006 Publish dual freq PF feed test results 09/2006 Full Q‐band bandwidth restored 09/2006 Complete W‐band receiver construction 09/2006 Begin CCB production science use 10/2006 Initiate eng shutdown for AZ track repair 06/2007 Complete eng shutdown for AZ track repair 09/2007 FIFO manual dynamic scheduling enabled 09/2007 Complete Zpectrometer construction 09/2007 Automated dynamic scheduling complete 09/2008 GBT pipeline processing begins 10/2008 Initiate W‐band user science operations 10/2008 Penn Array routine science operations begin 10/2008 Initiate Advanced Pulsar Backend development 10/2008 Full PTCS implementation complete 09/2009

Table 6.3 provides a list of high‐priority additional operational needs at Green Bank, together with their estimated cost in FY 2005 dollars.

Table 6.3 Additional Requested GBT Capabilities in FY 2006. Items Cost Replacement GBT LO1 Synthesizers $120,000 LF Network Analyzer $60,000 Spectrum Analyzer $60,000 Digital Oscilliscope $65,000 Test equipment $24,000 Fire Suppression equipment $35,000

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Items Cost Compressed air system dryer $10,000 Emergency generator $595,000 NetApp for control network $50,000 Old Jansky Lab switch replacement $8,000 Beowulf cluster $25,000 Vehicle replacement $90,000 MMIC Array university collabrontion $75,000

GBT Long Term Development Program

Until FY 2005, the GBT was pushing aggressively to achieve operation at 3mm via the Precision Telescope Control System Program, the Penn Array Camera, and the development of single‐ pixel heterodyne receivers covering the 68‐92 GHz and the 90‐115 GHz windows. Unfortunately, staffing and funding limitations in FY 2005 have meant that, while this remains our long‐term goal, the pace of this development program has had to be scaled back. Accordingly we have now adopted a phased approach. In the first three years of the five‐year plan, we will focus on providing excellent capabilities up to 6mm, with some initial 3mm work. More ambitious capabilities at 3mm will be delivered in the subsequent two years.

The key aspects of the GBT development plan over the next three years are as follows.

We will maximize our production science capabilities at wavelengths up to 6mm (Q‐band, 50 GHz), but no higher. We will provide outstanding productivity in this regime, with state‐of‐ the‐art new instrumentation (Caltech Continuum Backend, Zpectrometer), an easy to use flexibly‐scheduled observing system, and excellent data analysis facilities.

We will continue development of the Penn Array for demonstration of, and assistance in commissioning the GBT’s 3mm capabilities, and to perform a series of key 3mm science experiments. This provides the mechanism by which GBT will commence 3mm scientific operations. The Penn Array will, however, remain an expert user / P.I. collaboration instrument. The remainder of the GBT 3mm program will be postponed until winter 2008/09.

We will proceed with the next stage of a very stripped‐down PTCS project, to provide real‐time but stand‐alone measurement of the orientation of the elevation axle. This would feed dynamic pointing corrections into an otherwise unchanged antenna control system in a manner analogous to the current thermally‐derived dynamic corrections. This system would then compensate for all pointing effects below the elevation axle, including specifically azimuth track effects. The timescale for this development should be such that the system is in production use at the completion of the azimuth track refurbishment, and so can be used to compensate for the profound effects this will undoubtedly have on the current pointing model. If by mid FY 2007

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months from now it appears that this system cannot be made fully operational, we would drop back to a much less attractive, but considerably simpler static characterization of the track via inclinometry, a capability that has already been demonstrated in an engineering mode.

We will continue development of observing and data analysis software to further optimize scientific productivity and user friendliness of the GBT:

Throughout this period all observations will be performed, using ASTRID, by the execution of Scheduling Blocks (SBs) which have been defined in advance. In FY 2006, we will continue rounding out development on Astrid applications, most significantly to enable the management of GBT observations at the science program level. The intent is to leverage existing software and approaches for this purpose; both the JCMT and ALMA Observing Tools will be considered. Additional improvements include unifying tools for generating source lists and finding calibrators in the ASTRID environment, providing utilities for more completely interacting with the observation management database in Green Bank, and aligning databases in Green Bank with others across the observatory to protect the integrity of observational metadata. We will also support remote observing for trained observers, and improve the robustness of Astrid applications if required to support this capability.

Beyond FY 2007, observing systems work will focus on integrating additional observing modes for newly commissioned instruments. This will take advantage of the streamlined approaches for implementing software for new observing capabilities developed in 2003‐2005, which replaced one‐off style development which had been done in the past.

We will formally and aggressively pursue the implementation of full dynamic scheduling to optimize our use of high‐frequency weather and enable timely completion of projects. Additionally, we will achieve efficient fixed scheduling of crucial maintenance activities, VLBI/bi‐static radar or other observations that require coordination with other facilities, and monitoring projects. Three phases are planned: first, the long‐term processes and policies for dynamic scheduling will be articulated and agreed upon. Then, a pilot program will test the validity of assumptions, conduct measurements, consolidate the current Scheduling Block based observing process, and provide any required software changes. This will allow interactive, single user first‐in‐first‐out (FIFO) observing based on manual dynamic scheduling. In the final phase, dynamic scheduling will be automated and optimized at the science program level. All telescope activities, including science, commissioning, tests and maintenance will be flexibly scheduled in as automated a process as possible to best achieve scientific productivity goals.

For the pulsar community, we will explore development of a dual‐frequency (300/800 MHz) prime focus feed for pulsar observations. This was one of the highest priorities recommended by the recent pulsar review meeting.

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As noted, the key goals for the three year period FY 2006 through FY 2008 will be to provide outstanding science capabilities at wavelengths up to Q‐band (6mm), while the Penn Array will produce key science results and demonstrate the ability of the GBT to perform at 3mm. The main goal of the last two years of the GBT five year strategic plan will be to convert the Penn Array to common user operation, to provide a full 3mm observing capability including improved antenna performance and spectroscopic instrumentation, and to commence work on a 3mm spectroscopic camera. The details of this period are necessarily less certain, and will undoubtedly evolve. Nevertheless we will expect to make progress on the following major projects, as well as a number of smaller initiatives.

Conversion of Penn Array to common user status

After our experiences with commissioning and initial operation of the Penn Array in 2006 through 2008, the operational modes and required data reduction and processing steps will have been well understood and prototyped. Commencing in 2008, we will convert this instrument to full common‐user operation, including a data reduction pipeline.

Full Precision Telescope Control System

To achieve the required performance for 115GHz operation, we will need to complete the full PTCS implementation as proposed at the PTCS Conceptual Design Review.

Initial 3mm spectroscopic observing capabilities

Construction of the first (68‐92 GHz) module of a dual‐feed 3mm heterodyne receiver is already underway. The key limitations preventing deployment of this receiver during the first three year period are the comparatively more stringent requirements on antenna performance (c.f. the Penn Array), and the pressure on both scientific staff and good high frequency observing weather for commissioning and delivery of the 25‐50 GHz heterodyne instrumentation and the Penn Array. However we expect to complete construction of the hardware for the 68‐92 GHz receiver by end of FY 2006. This receiver will be commissioned and brought into operation at the start of FY 2009, for the winter 2008/09 observing season. This receiver may also provide the infrastructure (cryostat, etc) to allow initial testing of prototype MMIC array modules.

User‐friendliness, “end‐to‐end” processing, and virtual observatory initiatives

We will plan to participate fully in the NRAO wide initiatives in these areas. Where appropriate, we will move to common observation proposal, preparation and execution tools. This area will also include development of data analysis pipelines, a full searchable archive, and support for data mining activities and the like.

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Advanced Pulsar Backend

This would be a successor to the current GASP / CGSR‐II machines. A proposed specification would be:

• Very wide (~1GHz) bandwidth. A point of reference is ~600MHz of usable BW between 1650‐2250MHz. • High‐bit sampling. • Full‐Stokes capability. • Some built‐in RFI excision capability (i.e. transient wide‐BW and narrow‐band RFI removal. Our bandwidths now are limited by very strong narrow‐band RFI). • Ability to provide filterbank‐style output. • Ability to output coherently‐dedispersed subbands.

The machine would probably be a combination of DSP‐style hardware (i.e. Field Programmable Gate Arrays) and a computer cluster. Development of appropriate software would be a major issue. The two existing machines provide some of this capability now, but only over 64‐ 128MHz of bandwidth. They do all their processing on compute nodes and have no built‐in RFI excision. This machine would provide a major advance in observing capability.

Commencement of next generation array receivers (university collaborations)

The combination of the unique sensitivity, unblocked aperture and wide field of view of the GBT would be ideally matched by next generation array receivers. These would be major construction projects which we might hope to initiate during the FY 2009 – 2010 timeframe. They would be undertaken in collaboration with university consortia.

A large spectroscopic focal plane array at millimeter wavelengths would enable a powerful new set of scientific capabilities with the GBT, both as a stand‐alone instrument and in combination with millimeter‐wave interferometers. A. Readhead at Caltech and A. Harris at the University of Maryland are forming a consortium to investigate and develop the required basic technology. They have performed a very rough preliminary costing for a prototype array of some tens of pixels (to do science, plus demonstrate scalability and technology), and came up with some $3‐ 4M. The timescale would depend on all sorts of imponderables, but 3‐5 years seemed quite reasonable. Readhead and Harris would enthusiastically support a University/NRAO collaboration to develop such an instrument. We anticipate the bulk of the funding would come from an external NSF grant, but we would expect Green Bank staff would make a significant contribution to the project; this would help to ensure that it would be well integrated and supportable once installed on the GBT.

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Large format bolometer arrays have shown perhaps the most rapid advances in technology of any areas of millimeter wave technology. It is now quite feasible to build arrays of several thousand pixels, and this is in fact being done with the SCUBA‐2 project on JCMT. It would be reasonably straightforward technically to expand our current TES/SquidMUX architecture to 1000 pixels, and to duplicate that unit (e.g. ACT comprises three units of 1000 pixels each, each unit very similar to the Penn Array; the ACT test cryostat, which exists, is ~36 inches across). A large monolithic array is probably not feasible due to the difficulty of getting 1000’s of wires out from the array center (or requiring complex and undesirable SCUBA‐2 style SQUIDs at each TES), and the large needed size of lenses and filters. Under any scenario significant development in the area of TES detectors and optics will be needed, mostly due to size and long wavelength. Again, this would be an area that would be ripe for collaboration with external labs and universities. Similar to the MMIC heterodyne array, this would be a multi‐FTE, multi‐ year project, but with enormous scientific potential. The most prudent course for now is to bring the Penn Array online, evaluate the initial results from it, and then pursue the large‐ format camera if desired.

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Very Large Array

The VLA consists of twenty‐seven 25‐m antennas arranged in a wye configuration, with nine antennas on each 20 km arm of the wye. The antennas are transportable along a double rail track (Figure 6.3) and may be positioned at any of seventy two possible stations. In practice, the antennas are rotated among four standard configurations, which provide maximum baselines of 1, 3, 11, and 36 km. Additional “hybrid” configurations with a long northern arm are used to provide optimal sampling of sources in the south. Reconfigurability provides the VLA with variable resolution at fixed frequency or fixed resolution at variable frequency.

Figure 6.3. A 230‐ton VLA antenna is transported along the double‐rail system at roughly walking speed by the 90‐ ton transporter. Over the course of a year, more than 50 antenna moves are carried out for reconfiguration and maintenance purposes.

The VLA supports eight frequency bands which, generally, can be remotely changed by means of subreflector rotation. (The 74 MHz system consists of dipoles that are mounted periodically for short campaigns, then removed, due to minor impact on the aperture efficiency at some of the other frequencies.) Table 6.4 summarizes the current parameters of the VLA receiving systems. The VLA has full polarization capability in all continuum and spectroscopic bandwidths ranging from 50 MHz to 195 kHz. Within certain total bandwidth limitations, 512‐ channel spectroscopy is supported in all bands.

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Table 6.4. VLA Receiving Systems

Frequency Tsys Amplifier (GHz) (K) 0.070 to 0.075 10001 Bi-Polar Transistors 0.308 to 0.343 150 GaAsFET 1.34 to 1.73 33 Cryogenic HFET 4.5 to 5.0 45 Cryogenic HFET 8.0 to 8.8 31 Cryogenic HFET 14.4 to 15.4 108 Cryogenic 22.0 to 24.0 55 Cryogenic HFET 40.0 to 50.0 95 Cryogenic HFET 1 Tsys includes galactic background.

The VLA currently is undergoing a complete electronics renovation as part of Phase I of the Expanded VLA (EVLA) Project, (see chapter 5). Almost all new capability development is part of the EVLA program, so the description of the current VLA largely is limited to ongoing observing capabilities and infrastructure maintenance.

VLA Science Highlights in FY 2005

White Dwarf’s Re‐Ignition Spurs New Stellar Evolution Model

In 1996, V4334 Sgr, better known as Sakurai’s Object, rapidly brightened. Initially thought to be a nova explosion, the event soon was recognized as the first modern observation of a white dwarf re‐igniting after its nuclear burning had ceased. This provided a once‐in‐a‐lifetime opportunity to study the type of event that may be a significant source of carbon and carbonaceous dust in the Galaxy. The re‐ignition, only the third ever observed, (the others were in 1918 and possibly 1670), is believed to result when a small, hydrogen‐rich envelope is convectively ingested into the white dwarf’s helium shell, triggering a renewed nuclear flash. Earlier models predicted that this would cause the star’s luminosity to increase over a few hundred years. However, this evolution occurred 100 times faster, prompting development of a new model that predicts rapid reheating. The VLA observations revealed radio emission from freshly ionized matter, confirming that the rapid reheating has begun.

VLA Provides Key Data on Magnetar Outburst

When the Soft Gamma‐ray Repeater SGR 1806‐20 underwent a giant flare on December 27, 2004, the VLA became the prime tool for studying the burst’s afterglow, in part because the object was at the time too close to the Sun in the sky for many satellite observatories to safely observe. Two teams, including thirty three investigators from four continents, used the VLA to study this object, a magnetar. Results from the early observations include measurements of the

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fireball’s expansion speed (0.3c); estimates of the total energy of the flare; a non‐spherical and possibly changing shape for the fireball; and polarization measurements. HI absorption measurements by one team possibly have called into question the generally accepted distance to this object, with significant implications for models.

VLA Shows Young Galaxy with Black Hole, Almost No Stellar Bulge

VLA observations of 1148‐5351, the most distant quasar yet found, at z=6.4, show that the mass of molecular gas plus the mass of the presumed supermassive black hole at the core of the Active Galactic Nucleus (AGN) account for nearly the total mass of the system. This leaves little mass available for a central galactic bulge, and much less mass than standard black hole‐bulge relationships predict for such a bulge. This single example from the early universe of a young galaxy with a supermassive black hole but no significant bulge may serve as an important clue to the long‐standing question of whether the black hole or the bulge formed first, or coevally as some current popular models suggest.

VLA Accomplishments in FY 2005

Observing and User Programs

Over a number of years, the amount of scientific observing time used on the VLA has remained very stable at 76 percent or 77 percent of the number of hours in a year. The amount of lost time during these scientific observations also has remained quite constant, at about 4% of the number of scheduled antenna‐hours. During FY 2005, the amount of scientific observing remained at its usual level. The amount of downtime increased to roughly 10 percent of the possible antenna‐ hours due to the loss of two antennas that were being modified and used for prototype development for the VLA Expansion (EVLA) Project. In August 2005, the VLA has a maximum number of twenty four antennas, since four antennas are in various stages of EVLA modification. (Note that the VLA actually has twenty eight antennas, including twenty seven in operations and one that is rotating through its long‐term maintenance visit in the Antenna Assembly Building.)

Three large VLA programs were completed in FY 2005. These included the VLA Low‐ frequency Sky Survey, a survey of HI properties in twenty galaxies in the Virgo cluster, and another HI survey of nearby dwarf galaxies. In addition, a large program to study afterglows of gamma‐ray bursts detected by the newly launched Swift satellite began in January 2005.

The NRAO Rapid Response Science program now has been in place for the VLA for nearly two years. In FY 2005, NRAO put in place a system whereby “filler” programs scheduled to fill short gaps in the VLA schedule may be identified easily and are the primary candidates to be replaced by Rapid Response Science. This system was modified slightly for the aforementioned

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gamma‐ray burst program, enabling the more rapid overrides necessary to get rapid response to Swift triggers, particularly those from “short” bursts.

EVLA/VLA Transition

During FY 2005, a plan was developed for the checkout of EVLA antennas and their return to the VLA for scientific observing with the “old” antennas and correlator. This plan included an assessment of the scientific, engineering, and operational resources needed to bring the EVLA into operation, as well as a draft schedule for making new capabilities available to the scientific users of the EVLA. The schedule for bringing antennas back into the VLA has slipped somewhat from FY 2005 to early FY 2006, due to required revisions on some of the prototype electronics modules.

VLA + Pie Town Link

The fiber‐optic link between the Pie Town VLBA antenna and the VLA was offered to observers once again in FY 2005. This link doubles the longest baseline of the VLA, improving the angular resolution by a factor of two for complete syntheses of northern sources, and somewhat less for shorter observations or sources at low declinations. During the A configuration period from September 2004 through January 2005, a total of twenty one observing programs used the Pie Town link in forty sessions for a total of 272 hours of observing, roughly 15% of the total A configuration time.

Dynamic Scheduling

During the antenna reconfiguration in July 2005, a first attempt was made at dynamic scheduling of the VLA using pieces of both the VLA and EVLA software systems. This test was successful, but required significant human intervention for successful operations. The experience from this three‐day test will be used to refine further the requirements and development plan for both VLA and EVLA dynamic scheduling.

190 MHz System Installation

Scientists from the Smithsonian Astrophysical Observatory (SAO) and NRAO proposed at the end of FY 2004 to install 190 MHz observing systems on the VLA to search for redshifted neutral hydrogen emission from the Epoch of Reionization. Hardware funded by SAO was installed on several VLA antennas for test purposes, with considerable engineering and testing support supplied by NRAO personnel. New digital television stations have caused significant interference problems in the key frequency range of 186‐198 MHz, but negotiations with station personnel may result in the possibility of observations being done at night at times when the

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television stations may be switched off. Two reviews of system engineering and readiness were held in FY 2005, with a final decision on installation to be made in September 2005.

Long Wavelength Development Array

Scientists from the Southwest Consortium for radio astronomy are aiming to build an array of low‐frequency radio antennas (20 to 88 MHz) spread over several hundred kilometers of southern New Mexico and West Texas. This Long Wavelength Array (LWA) would be used for low‐frequency astronomy and ionospheric studies. The first phase of LWA, the Long Wavelength Development Array (LWDA) has been funded, and would involve the placement of a “station” consisting of 256 dipole antennas on the VLA site. This station, together with a later station about 50 km from the VLA site, would be hooked to the VLA via fiber optics and used in conjunction with the VLA 74 MHz receiving system. In FY 2005, a location for the LWDA was selected on the VLA site, and a design review was carried out. Groundbreaking for the LWDA will occur late in FY 2005 or early in FY 2006.

Water Vapor Radiometry

Lack of funding and lack of personnel prevented any significant progress from being made on Water Vapor Radiometry in FY 2005. Given a flat NSF budget, we anticipate little or no work in this area over the next several years.

Infrastructure

Degenerated azimuth bearings on antennas 16 and 18 were replaced by new bearings in FY 2005. These were the ninth and tenth bearing replacements on the VLA since the first one was replaced in 1993; typically one or two bearings now are replaced each year.

In 1998, an internal inspection of the VLA track system found one‐third of the railroad ties to be past their service life. To replace these ties and overcome their deterioration rate, the ties need to be replaced at a rate of 5,000 per year for twenty years. Infrastructure funding in 2001 enabled the purchase of a three‐year supply of ties and ballast, but personnel resources have prevented NRAO from maintaining the rate of 5,000 ties per year. In calendar year 2004, about 4,400 ties were replaced, the most in several years; a total is not yet available for FY 2005. Figure 6.4 shows repairs under way at one of the track intersections, where antenna and transporter must be rotated 90 degrees in order to install the antenna at a new location.

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Figure 6.4. Repair of a rail intersection, where antenna and transporter are turned by 90 degrees for installation at a new pad.

The standard Astronomical Image Processing System (AIPS) used for both the VLA and VLBA continues to be supported by NRAO for export to its entire user community. In FY 2005, a frozen December 31, 2004 version of AIPS and a daily‐updated December 31, 2005 version were produced. Additional models were added to the software for the primary VLA flux‐density calibrators, and considerable work was done to improve the porting of AIPS to MacIntosh computers. Standard desktop computers now run AIPS approximately 50‐100 times faster than the workstations of the early to mid‐1990s. Over the course of calendar 2004, astronomical users from about 1,000 unique computer addresses downloaded either the December 31, 2004 or December 31, 2005 versions of AIPS, with more than 200 making at least occasional use of the “midnight job” to acquire and install the latest updates to the software. Also during FY 2005, the primary AIPS architect and developer, Eric Greisen, was awarded the van Biesbroeck award of the American Astronomical Society, primarily in recognition of his long‐term service to the community for developing and supporting AIPS.

VLA Data Archive

The NRAO data archive went on line in October 2003, and includes a complete set of all raw VLA data since 1976, plus some VLBA data and a small amount of GBT data. The VLA data sees the most use, and now has reached a roughly steady state of over 100 Gbytes of downloads per month. Roughly half of the data downloaded are non‐proprietary data (more than twelve months since the last observation in a program), while the rest are proprietary data downloaded from the archive for the initial analysis by members of the proposing teams. In FY 2005, a complete set of VLA archive data was transferred to an additional site at the National Center for Supercomputing Applications. Also in FY 2005, a small project was begun to image all the 5

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GHz and 8.4 GHz data from a single B configuration (several months long) in 1999. The goal of this program is to produce science‐quality images that can be made available via the National Virtual Observatory, and to determine the resources required to carry out a similar program for a much larger fraction of the VLA archive.

VLA Plans for FY 2006

Observing and User Programs

In FY 2006, the general nature of VLA observing will remain the same as in FY 2005. Five new Large Proposals for more than 200 hours of VLA observing were received at the June 1, 2005 proposal deadline. We anticipate that approximately two of these programs will be granted observing time by the Large Proposal Review Committee and will commence observations during FY 2006, while the large program of afterglow studies associated with Swift will continue. In addition, a special call for extragalactic deep/blank fields has been made for the October 3, 2005 proposal deadline, and we expect several medium‐size programs (of order 100 hours) to be approved from this special call.

Early in FY 2006, the VLA will be reconfigured from C to D configuration. Thus, the primary observing configurations offered in FY 2006 will be the D (smallest), A (largest), and B (second largest) configurations of antennas.

The tenth Synthesis Imaging summer School will be held during FY 2006. This year, the school will shift from Socorro to Albuquerque, where it will be held with new co‐sponsorship from the University of New Mexico. We expect the usual enrollment of about 150 students in the week‐ long intensive school in aperture synthesis theory and techniques. Figure 6.5 shows the participants from the ninth summer school.

Figure 6.5. Participants in the Ninth Synthesis Imaging Summer School, shown in front of the Array Operations Center.

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EVLA/VLA Transition

Early in FY 2006, the first of several modified EVLA antennas will be returned to the VLA for observing, and we expect the maximum number of operational antennas to return to twenty five or more, well before the end of the year. These antennas will have passed their electronics and scientific checkouts, and will be controlled by a hybrid system of VLA and EVLA software. Their data will be transmitted to the control building via the EVLA fiber‐optic system, then converted back to analog data to mimic old VLA antennas and be fed into the VLA electronics system. Most existing VLA frequency bands will be supported on the EVLA antennas.

The venerable Modcomp control computers for the VLA will be decommissioned during FY 2006. This will result in control of the VLA by an interim version of the EVLA control software, with provisions made to operate both the old VLA antennas and the new EVLA antennas.

A new on‐line proposal submission tool for the VLA will debut during FY 2006. Although this tool will be used for the VLA, its design is intended to support the EVLA, and specifically to support the analysis and construction of the scheduling blocks that will be used in the EVLA dynamic scheduling system.

Initial plans had scheduled first tests of a few‐station prototype of the EVLA correlator using real VLA observations during FY 2006. The latest schedule provided by our Canadian partner for this prototype correlator now shows a slip into FY 2007, so we anticipate that FY 2006 will include only the development of a plan for exercising this prototype.

VLA + Pie Town Link

The VLA+Pie Town real‐time link over a fiber‐optic connection will be offered while the VLA is in A configuration from February 2006 through May 2006. The last several A configurations saw roughly 15% of the VLA observing time allocated to the Pie Town link. In the FY 2006 A configuration, we anticipate that the fractional observing time with Pie Town may be reduced to about 10%, because of the pressure of performing EVLA development at the same time we support the Pie Town link.

Dynamic Scheduling

In FY 2006, development of dynamic scheduling will continue with further tests on the VLA. We do not anticipate that this dynamic scheduling will become a truly operational mode for VLA until 2007 or 2008.

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190 MHz System Installation

If installation of the 190 MHz system on the VLA is approved during its final review, first observations are anticipated during the D configuration in December 2005 and January 2006. These observations will be largely in the nature of extended tests, but also may provide the first significant scientific results on the ionization of the intergalactic medium by the first quasars.

Long Wavelength Development Array

Installation of the VLA‐hosted prototype station for the LWDA will be completed in FY 2006. First interference fringes against VLA antennas at 74 MHz also are planned for FY 2006.

Infrastructure

One azimuth bearing will be replaced on a VLA antenna, probably on antenna 26. This will deplete the stock of new azimuth bearings, except for one kept on hand for emergency repairs. Funding will be sought for refurbishment of several of the azimuth bearings removed from VLA antennas in FY 2004 and FY 2005, so that these reworked bearings may be used for repair of additional antennas.

Approximately 3,500 rail ties will be replaced on the VLA rail system in FY 2006. Due to funding limitations, the budget for new rail material has been reduced from $300K to $200K annually, permitting purchase of materials for only 3,500 ties instead of 5,000. The new replacement rate of 3,500 ties per year is below the 5,000 recommended by an independent consultant five years ago.

A frozen December 31, 2005 release of the AIPS software will be made, and the daily‐updated December 31, 2006 version will be initiated. A binary version of AIPS with a new higher‐ performance compiler will be made available to the astronomical community.

Since the EVLA construction will make the VLA a forefront scientific instrument through 2030, attention must continue to be paid to long‐term infrastructure maintenance. There are a number of important infrastructure projects that cannot be accomplished within the baseline budget in FY 2006. Among these are the refurbishment of old azimuth bearings, acquisition of a T3 (43 Megabits per second) communication line from the VLA to the Array Operations Center (AOC), an upgrade of the VLA Atmospheric Phase Interferometer, an increase to the recommended long‐term rate of replacement of railroad ties, and initiation of a long‐term program for replacing the vehicles at the VLA site. Costs of these items range from $50K to $130K in FY 2006, and some are projects that need multi‐year investments.

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VLA Data Archive

The pilot imaging project for the VLA data archive, described in the accomplishments for FY 2005, will be completed during the first quarter of FY 2006. A plan will be constructed for extension of this pilot project to additional VLA archive data, and funding will be sought.

VLA Deliverables in FY 2006 and Beyond

Table 6.5 summarizes key VLA deliverables over the next few years. Since funding in the baseline budget permits very little new development beyond the EVLA project, almost all these deliverables are in the areas of continued operations and infrastructure maintenance.

Table 6.5. VLA Milestones with Baseline Budget Item Delivery Date Release new VLA proposal tool 12/2005 Freeze AIPS version 31DEC05, begin 31DEC06 12/2005 Return first EVLA antennas to VLA 1/2006 Complete archive imaging pilot project 1/2006 Initiate next Pie Town link observations 2/2006 Decommission Modcomp computers 7/2006 Replace 3,500 railroad ties 9/2006 Replace one azimuth bearing 9/2006 First on‐sky test of EVLA prototype correlator 3/2007 Replace 3,500 railroad ties 9/2007 Replace one azimuth bearing 9/2007 Initiate operational dynamic scheduling 12/2007 Initiate next round of VLA antenna painting 9/2009 EVLA correlator operational; VLA becomes EVLA 9/2010

Table 6.6 provides a prioritized list of additional capabilities for the VLA, together with their estimated cost in FY 2005 dollars.

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Table 6.6. Prioritized additional VLA capabilities in FY 2006

Item Cost Refurbish three azimuth bearings $75K Expand VLA/EVLA e2e capabilities $250K/yr Initiate VLA student grants program $200K Expand VLA archive imaging project $200K/yr Acquire wideband link from VLA to AOC $58K/yr Upgrade VLA Atmospheric Phase $50K Interferometer Carry out Phase II of WVR project $120K Increase tie replacement rate to 5,000/yr $130K/yr Initiate long‐term VLA vehicle plan $100K Digitize fiber link from Pie Town to VLA $130K

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Very Long Baseline Array

The VLBA is an instrument devoted to Very Long Baseline Interferometry (VLBI), with ten antennas distributed throughout the United States in a configuration which optimizes the distribution of baseline lengths and orientations. It is the only such dedicated VLBI instrument in the world. The VLBA has baselines between 200 and 9,000 km, which provide angular resolution as fine as 0.1 milliarcseconds at 86 GHz. The shorter baselines, and hence the highest concentration of antennas, are near the VLA for optimal joint observations. The antennas are 25 meters in diameter and of an advanced design which allows good performance at 43 GHz and useful performance at 86 GHz. Table 6.7 summarizes the performance of the instrument at its ten frequency bands. The antennas are operated remotely from the Socorro Array Operations Center (AOC); local intervention is required only for recording media changes, routine maintenance, and troubleshooting. With our old tape‐based system, now being moved toward retirement, the recording rate has been limited to an average of 128 Megabits per second (Mbps) which fills two tapes every 24 hours. New, disk‐based, recorders are being installed that should eventually permit recording rates up to 1024 Mbps with media changes once every 24 hours (or longer). The sustainable recording rate for the disk system will start near 128 Mbps, but will increase to higher values as funding permits the acquisition of more disk media.

Table 6.7. VLBA Receiving Systems Frequency Range Typical Zenith SEFD Typical Zenith (GHz) (Jy) Gain (K Jy -1) 0.312 to 0.342 2217 0.097 0.596 to 0.626 2218 0.090 1.35 to 1.75 295 0.093 2.15 to 2.352 344 0.089 4.60 to 5.1 289 0.132 8.0 to 8.82 299 0.118 8.0 to 8.8 391 0.111 12.0 to 15.4 543 0.112 21.7 to 24.1 976 0.104 41.0 to 45.0 1526 0.078 80.0 to 96.03 3500 0.030 1 System Equivalent Flux Density: The source flux density which doubles the system temperature. 2 With dichroic. 3 All except Hancock and St. Croix installed. Two antennas only cover the frequency range up to 90 GHz.

The VLBA correlator is located at the AOC, and is able to correlate as many as eight input data channels from each of twenty antennas simultaneously. For most modes, the correlator can provide 1,024 spectral points per baseband channel, and up to a maximum of 2,048 spectral

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channels per baseline can be provided for each recorded signal. In order to join its long baselines with the shorter baselines of the VLA and perform high‐sensitivity imaging over a wide range of scales, increased bandwidth is critical for the VLBA. This will require a substantially increased capability for VLBA data acquisition and correlation, which can probably be done most cost‐effectively by use of available capacity on the EVLA correlator and by upgrades to the recording system and station electronics.

VLBA Science Highlights in FY 2005

High Speed Pulsar

Over a period of twenty two months, and as part of a larger, long‐term project, VLBA measurements of the pulsar B1508+55A have revealed that its associated neutron star has the fastest speed yet observed: nearly 1,100 kilometers per second. Previous estimates of neutron star speeds have depended on lower accuracy distance estimates. For pulsar B1508+55A, however, the VLBA obtained a precise, direct distance measurement and a well‐determined speed. Though it has long been known that supernova explosions can “kick” neutron stars to significant speeds, the high speed of this neutron star pushes the limits of our current understanding, and this discovery is difficult for the latest models of supernova core collapse to explain. Located at a distance of approximately 7,700 lights years, this neutron starʹs presumed birthplace is among giant stars in the constellation Cygnus, in the plane of the Galaxy. Since the supernova explosion, nearly 2.5 million years ago, the pulsar has moved across about a third of the night sky as seen from Earth.

Stellar‐Wind Collision Region’s Motion is Tracked

The motion of a wind‐collision region in the binary pair WR140 has been tracked. The pair consists of a Wolf‐Rayet star and an O star. The region where their stellar winds collide is seen as a bow‐shaped arc of radio emission that rotates as the orbit progresses. This VLBA observation has allowed refinement of the orbit’s inclination and a definitive determination of the system’s distance. The new data, which is inconsistent with model predictions, will ultimately allow better understanding of the nature of both Wolf‐Rayet stars and of wind‐ collision regions.

VLBA Measures Proper Motion, Rotation of M33

Using VLBA observations made over a period of 2.5 years, astronomers have directly measured both the proper motion and the rotational motion of M33. This is the first proper‐motion detection ever made of a galaxy that is not a satellite of the Milky Way. Combined with radial‐ velocity measurements, this work provides the first three‐dimensional measurement of the galaxy’s motion in space. M33 is a satellite of M31, and this work will refine the orbit of M33

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and help determine if it has undergone close encounters with M31 in the past. The measurement of such miniscule angular motion was done by observing water masers in interstellar clouds within M33.

Cores of Extragalactic Radio Sources Shown to Contain Microarcsecond Structures

The morphologies of compact extragalactic radio sources imaged with the VLBA have been compared to their scintillation properties. The short time‐scale scintillation of compact sources is thought to be caused by the interstellar medium in our own galaxy, and reveals the presence of radio‐emitting structures that are only a few micro‐arcseconds in size. Statistical studies show that the VLBA images of scintillating radio sources are significantly more core‐dominated than images of a comparison sample of non‐scintillating sources. This demonstrates conclusively that the micro‐arcsecond component is directly associated with the core of the radio source, and hence with the actual nucleus of the host galaxy. At the typical large distances of the radio sources, this radio component is no more than a few thousand astronomical units in size, probably only a few hundred times the gravitational radii of the central massive black holes.

VLBA Accomplishments in FY 2005

Observing and User Programs

For the first nine months of FY 2005, the VLBA performed successful astronomical observing for 50 percent of the time, a total of 3,262 hours out of a total of 6,552 hours. The scheduled observing was 3,422 hours, and total downtime was about five percent. (All numbers are scaled to a 10‐element array, so that ten hours of down time for a single antenna or one hour of downtime for the whole VLBA are each counted as a total of one hour of down time.) Since most observing is done with dynamic scheduling, the observing programs are matched to the predicted weather so that the proportion of good data at high observing frequencies is better than for telescopes operating with fixed schedules. The number of observing hours has been restricted by the tape‐limited data transfer to the correlator, discussed later in the Mark 5 section. Many observations request data‐recording rates higher than the sustainable value of 128 Mbps because of the scientific requirements on sensitivity; such observations result in idle time for the VLBA after the tape recorders are full. Scaled to the sustainable data rate of 128 Mbps, the VLBA observed for 4,331 (128Mbps‐hr), or 66 percent of the time.

The observations for a large VLBA proposal, recommended by the Large Proposal Review Committee, began late in FY 2004 and continued throughout FY 2005. This program involves long‐term monitoring of the structure of active galaxies at 15 GHz. It will end early in FY 2006, after accumulating more than 300 hours of observing time. The long‐term (since 1999) support of NASA’s Gravity Probe‐B mission, through VLBI observations of the astrometric reference

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star, is scheduled to end by the end of FY 2005, unless the weakness of the reference star requires 1‐2 additional observations in FY 2006.

Mark 5 Recording System

VLBI observatories around the world are moving rapidly away from tape‐based and towards disk‐based recording systems (Mark 5). Disk‐based recording has many advantages over traditional tape‐based systems, including lower error rates, greater bandwidth, increased capacity, and improved maintenance. The cost of a single Mark 5 recording unit is less than 2% of the cost of the two tape drives that are being replaced. The cost of the media, however, while cheaper than tape, is still significant. The last tape purchases made by NRAO were at a rate of about $2.00 per Gigabyte, including the glass tape reels, whereas a 2‐Terabyte disk module (including the housing plus eight 250‐Gigabyte disks) could be procured for $1,340, or $0.67 per Gigabyte, in July 2005.

NRAO took its first steps toward conversion to Mark 5 in FY 2004. It was anticipated that a significant amount of the conversion might be paid for by NASA as part of a spacecraft navigation program (see below); unfortunately, funding limitations at NASA precluded development of operational spacecraft navigation. Therefore, in FY 2005, NRAO ceased all significant maintenance efforts on the old tape‐recording systems, as well as temporarily delaying other infrastructure spending, to accelerate the conversion to Mark 5. The continuing decrease in the price of large‐format disks assisted in this acceleration. By July 2005, five VLBA stations had been converted to Mark 5 full time, with tape drives decommissioned at three of those stations. Additional purchases were made or in the pipeline so that eight VLBA stations will be converted fully to Mark 5 systems by the end of FY 2005. The removal of the tape drives at many stations began contributing to an upturn in total observing time and correlator efficiency by late FY 2005.

High Sensitivity Array

At the beginning of FY 2005, NRAO instituted the High Sensitivity Array (HSA) of antennas for VLBI. This provided a formal proposal opportunity for astronomers to simultaneously propose for a VLBI array consisting of the VLBA, Green Bank Telescope, phased VLA, Effelsberg, and Arecibo. The HSA combines the excellent aperture‐plane coverage of the VLBA with the outstanding sensitivity of the additional telescopes with apertures ranging from 100m to 305m, thus increasing the sensitivity of VLBI observations by factors of at least 5 to more than 10 in the Arecibo declination range (at frequencies below 10 GHz). Approximately twenty HSA programs were observed in FY 2005; typical scientific targets included radio quiet quasars, super‐starburst galaxies, searches for central images of gravitational lenses, extragalactic water megamasers, and nearby supernova remnants. First scientific results from these observations are expected to be published in FY 2006.

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Spacecraft Navigation

A VLBA Spacecraft Navigation Pilot Project began in August 2003, and was concluded successfully with the issuance of a final report in December 2004. The Project, funded by NASA, studied several aspects of VLBA phase‐referencing measurements as a vital adjunct to conventional spacecraft navigation. Several observations of four different spacecraft en route to Mars or in Mars orbit, as well as the Cassini mission to Saturn, were taken and analyzed; local astrometric accuracy well under 1 milliarcsecond was achieved for several spacecraft. Based on these results, NRAO submitted a project plan to NASA for complete implementation of an operational capability for spacecraft navigation, which would include a routine dynamic observing capability for spacecraft as well as implementation of a 26‐40 GHz receiving system on the VLBA antennas. Unfortunately, NASA budget reductions precluded funding of this implementation plan, so the VLBA spacecraft navigation program has been shelved.

Huygens Probe

In January 2005, eight VLBA antennas plus the GBT were used to record the faint signals from the Huygens Probe as it descended through the atmosphere of Saturn’s major satellite, Titan. Tracking of the Doppler signals is being used by the Jet Propulsion Laboratory to reproduce spacecraft motion along the line of sight to Earth, while the VLBI data are being analyzed at the Joint Institute for VLBI in Europe to extract information about the winds across the line of site. By late FY 2005, the faint spacecraft signals had been extracted from all VLBA stations except for one hampered by radio frequency interference, and detailed analysis was under way; scientific results are expected in FY 2006. Support of this Huygens Probe experiment also led to the supply of six Mark 5 recording systems for use at NRAO, hastening the process of conversion from tape to disk recording systems.

High Frequency Systems

The major new frequency capability being developed for the VLBA over the last several years has been the addition of 80‐96 GHz receivers to most of the antennas. This has been funded partly out of the NRAO operating budget and partly by the Max Planck Institute for Radioastronomie (MPIfR). For the last two years, only eight antennas have been equipped; the wet weather at St. Croix and the poor subreflector at Brewster meant that it was not worth spending the money to equip either antenna. In addition, the antenna performance at Hancock has been poor, with an aperture efficiency well under 10% at 86 GHz.

In late FY 2004, a resurfaced antenna subreflector (originally on the Pie Town VLBA antenna) was installed at Brewster to replace its poorly performing subreflector. This refurbished subreflector yielded a 43 GHz performance that was more than 25% better than previously seen at Brewster, indicating that improved 86 GHz performance was possible. Therefore, the 86 GHz

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receiving system was moved from the poorly performing Hancock antenna and installed at Brewster in early FY 2005. Subsequent tests indicated that the Brewster antenna had been improved to an aperture efficiency of approximately 25% at 86 GHz, so that Brewster now is one of the best‐performing high‐frequency VLBA antennas. Installation of a refurbished subreflector and panel‐repositioning at an average antenna, Pie Town, failed to improve the performance as expected, and little further progress has been made because of the lack of available personnel.

Infrastructure

The analog tachometers on the VLBA antennas have long been expensive, high maintenance items. A program was started in the first quarter of FY 2004 to replace the analog tachometers with low‐noise digital tachometers. By the end of FY 2005, the new digital tachometers will be installed on 8‐9 of the 10 VLBA antennas, all except Mauna Kea and possibly North Liberty.

During early 2005, it became apparent that the St. Croix VLBA antenna was suffering from increasingly severe rust damage due to the humid salt air at this seaside site. In response to this situation, a maintenance visit to St. Croix was scheduled to replace the previously planned trip to Mauna Kea. (Because of the high costs, “tiger‐team” visits to the two island sites generally do not take place in the same year.) In April 2005, a three week maintenance visit was made to St. Croix to repair the worst rust damage (Figure 6.6). Even a visit to St. Croix every other year, more often than for the other VLBA sites, may not be sufficient to keep up with the worst of the rust damage, so NRAO now is contemplating an annual maintenance visit to St. Croix if funding permits.

Figure 6.6. Left: Sample image of rust damage on the sub‐reflector support leg at St. Croix. Right: Antenna mechanics patching the St. Croix sub‐reflector supports.

During July 2005, the two site technicians at St. Croix completely overhauled the cryogenics system of the antenna. All seven sets of cryogenic lines were replaced, including all rigid and flexible Aire Equip fittings. A special plastic coating was developed for the new fittings to

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prevent corrosion in the high‐humidity, high‐corrosion environment at St. Croix. The electrical wiring, high temperature protection, fan motors, and electrical contactors on all the cryogenic compressors were replaced. Charcoal traps were rebuilt and evacuated, and the vacuum pumps were serviced. The overhaul was completed with the evacuation, cooling, and testing of the complete cryogenics systems and associated receivers.

At the same time as the St. Croix cryogenics overhaul, a standard tiger team maintenance visit was made to the VLBA antenna in Los Alamos. A visit to Hancock was postponed due to the high cost of the long St. Croix visit, and may be replaced by a North Liberty visit in September 2005, if funding permits.

VLBA Data Archive

By the end of FY 2005, all VLBA data back to the beginning of January 2001, and some earlier data, had been loaded into the on‐line VLBA data archive. This on‐line archive is now is 14 TB and beginning to see significant use; several refereed papers using VLBA archival data were published in calendar year 2004, the latest year for which data are available.

VLBA Plans for FY 2006

Observing and User Programs

With the advent of the Mark 5 recording system on the VLBA, (see below) we anticipate a significant increase in the available VLBA observing time. We expect that the fraction of hours in the year spent on scientific observations will increase from 50% annual to a number closer to 60%, with the effective hours of recording at 128 Mbit/s exceeding 70%.

A large VLBA program utilizing astrometry of maser sources in our Galaxy, aimed at improving our knowledge of the structure of the Milky Way, was approved and began in late FY 2005. The observations for this program will continue throughout FY 2006. In addition, two other large VLBA programs are pending; each requests more than 1,000 hours of observing for monitoring or exploration of “blazer” sources, at least partly in anticipation of the launch of the Gamma‐ray Large Area Space Telescope (GLAST) in FY 2008. We expect that at least one of these programs will be approved for a substantial fraction of its proposed observing time and will begin observations in FY 2006.

Discussions with the GLAST project are under way for provision of long‐term dedicated VLBA observing time in conjunction with GLAST after its launch. We anticipate that an agreement will be reached in FY 2006 for dedicated observations to begin after GLAST launch in FY 2008.

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Mark 5 Recording System

In FY 2006, we expect completion of the conversion of the stand‐alone VLBA to Mark 5 operations, with all 10 VLBA stations using Mark 5, accompanied by 10 playback devices at the correlator. In FY 2006, we will need to spend about $125 K to complete this conversion, $49K for three more Mark 5 systems and $55K‐$80K for 40‐60 more disk modules. An additional goal, which may not be possible within our baseline budget, would be to complete conversion of the entire HSA to Mark 5 recording. This would require two additional recording units, for the VLA and GBT, four additional playback drives at the VLBA correlator, one spare, and about twenty four disk modules. An additional goal is to establish the capability for input of 20‐ station experiments to the correlator using Mark 5 playbacks, requiring an additional six recorders beyond the complement needed for HSA. This presently is a lower priority than acquiring the additional disk media that will enable the VLBA to operate for more time at 256 Mbit/s or 512 Mbit/s instead of the previously sustainable rate of 128 Mbit/s; the increased data rate will enable additional science return by improving most sensitivity‐limited observations.

In the longer run, NRAO plans to convert the Mark 5A recorder and playback units to the Mark 5B system under development by Haystack Observatory and Conduant Corporation. The Mark 5B ultimately will enable recording at 2 Gbit/s, possibly 4 Gbit/s using multiple disk modules. Such a high data rate will enable an increase in continuum sensitivity by a factor of 4‐6 relative to the currently sustainable 128 Mbit/s. Since it is well beyond the sustainable rate of the VLBA correlator, this also will require development of an interface to the EVLA WIDAR correlator, which is being constructed with VLBI capability along with the standard ability to input EVLA data.

The High Sensitivity Array (HSA)

The High Sensitivity Array will continue in FY 2006, and we expect to observe about 20 more programs with the VLBA, GBT, and phased VLA. As mentioned above, we aim to convert the entire HSA to Mark 5 recording as soon as possible; with the baseline budget, that is unlikely to be possible until at least FY 2007.

The VLBA will continue to participate in the Global VLBI observing sessions that are carried out three times per year. By using antennas in the U.S. and Europe together, the opportunity arises for increased sensitivity and better resolution than could be achieved with either the U.S. or Europe alone. Proposals for Global VLBI observations are submitted separately to NRAO and to the European VLBI Network (EVN), refereed separately by the VLBA and EVN referees, with time allocated by joint decision between the VLBA and EVN program committees. During FY 2006, the three Global VLBI sessions will take place in October/November 2005, February/March 2006, and June 2006.

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High Frequency Systems

No significant work on improvement of high‐frequency systems will take place in FY 2006. Since the 86 GHz receivers are somewhat fragile, it is strongly desired to spend approximately $50K to build up a ninth (spare) receiver; currently there is no 86 GHz spare for the VLBA. A lesser priority is the acquisition of an additional receiver for the Hancock station. This is not a cost‐effective purchase unless the aperture efficiency at Hancock is improved; no work will be done on this improvement due to the lack of available personnel.

NRAO will continue to participate in global 3mm VLBI observations with several observatories in Europe, in addition to the dynamically scheduled VLBA‐only observations. Two sessions are scheduled in FY 2006, one in October 2005 and one in April 2006.

Infrastructure

Tiger team maintenance visits will be made to Mauna Kea, Hancock, and St. Croix, if there is sufficient budget to send teams to both island sites. The analog tachometer at Mauna Kea will be replaced with a digital tachometer; together with a tachometer replacement at North Liberty in late FY 2005, this will conclude the tachometer conversion project.

One of the spare maser clocks for the VLBA requires repair, with a cost estimate of $45K. Each VLBA station relies on such a clock for its accurate short‐term timekeeping, and cannot usefully make observations without the maser clock. Within our present baseline budget, this maser repair will not take place, and the VLBA will be reduced from three spare masers to two. (Note that a new maser costs more than $250K.)

VLBA Data Archive

In FY 2006, we will continue to load VLBA data into the on‐line data archive. We anticipate that the entire VLBA archive will be put on‐line by the end of FY 2007.

VLBA Deliverables in FY 2006 and Beyond

Table 6.8 summarizes key VLBA deliverables over the next few years. Since funding in the baseline budget permits little new development, almost all these deliverables are in the areas of continue operations and infrastructure maintenance.

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Table 6.8. VLBA Milestones with Baseline Budget Item Delivery Date Eight full‐time Mark 5 stations 10/2005 Completion of digital tachometer conversion 6/2006 Ten full‐time Mark 5 stations 6/2006 Paint St. Croix antenna 6/2006 Observing increase to 58% of hours in year 9/2006 Maintenance visits to HN, MK, and SC 9/2006 Observing increase to 62% of hours in year 9/2007 Conversion of HSA to Mark 5 9/2007 Entire VLBA archive on line 9/2007 Maintenance visits to KP, OV, and BR 9/2007 Begin dedicated GLAST observations 3/2008 Conversion of VLBA from Mark 5A to Mark 5B 9/2008 Increase of sustainable data rate to 256 Mbps 9/2008 Increase of sustainable data rate to 512 Mbps 9/2010 Implementation of EVLA correlator for VLBI 9/2011

Table 6.9 provides a prioritized list of additional capabilities for the VLBA that are desirable for FY 2006, together with their estimated cost in FY 2005 dollars. Some of these are listed as milestones for later dates in Table 6.5, even though no funding is yet identified for them. Acceleration to FY 2006 would require additional funds in the FY 2006 budget.

Table 6.9. Prioritized additional VLBA capabilities Item Cost HSA conversion to Mark 5 in FY 2006 $150K Initiate student grants program $100K Increase sustainable rate to 256 Mbps in FY 2006 $268K Repair third spare VLBA maser $45K Increase correlator capacity to 20 Mark 5 stations $100K Increase sustainable data rate to 512 Mbps in FY 2006 $600K Construct spare 3mm receiver $50K Improve Hancock surface and install 3mm receiver $150K

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Central Development Laboratory Summary

The CDL supplies unique devices to other NRAO facilities and to the astronomical community for use in instrumentation, in particular low‐noise amplifiers, MMIC circuits, cooled mixers, passive electromagnetic components, digital data processing systems, and specialized receivers.

During FY 2006, the following projects and activities are scheduled:

CDL Projects FY 2006 Summary Low‐noise cooled HFET amplifiers Keep pace with EVLA receiver needs Complete designs for 4‐8, 8‐12, 12‐18 GHz Develop new designs for 60‐90 and 75‐115 GHz using best available transistors MMIC development Design power amps for ALMA Band 10 LO Revise module for EVLA WVR Investigate ultra‐wideband components Cooled mm‐wave mixers Measure 385‐500 GHz SIS mixer Measure HEB mixer performance Evaluate NbTiN SIS mixers Electromagnetics Design and test 2‐4 and 12‐18 GHz EVLA feeds Develop 300/600 MHz GBT prime focus feed Design new 1.30‐1.45 GHz GBT prime focus feed Solar Radio Burst Spectrometer Deploy new Phase III spectrometer Install 1‐3 GHz receiver Develop broadband components

Cooled HFET Development

The NRAO has worked on the development of HFET (heterostructure field‐effect transistor) amplifiers for many years and is the recognized leader of cooled HFET amplifiers for radio astronomy use. The highest‐frequency amplifiers cover the band 68‐116 GHz with noise performance comparable to SIS mixers and much wider instantaneous bandwidth.

The NRAO has produced hundreds of advanced HFET amplifiers for use on NRAO telescopes and for others in the radio‐astronomy community and other research areas. These range from low‐frequency amplifiers (< 1 GHz) used in fundamental particle physics and magnetic‐ resonance imaging development to the highest attainable frequencies for cosmic microwave background radiation experiments. At the lowest frequencies, special balanced amplifiers have

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been developed which largely eliminate the need for bulky isolators and have better immunity to the effects of interference.

Accomplishments in FY 2005

It is vital to the new EVLA receiver plan that we have new wideband amplifiers, particularly for the 1‐2, 2‐4, and 4‐8 GHz bands, which can be used in receivers having the high dynamic range needed to cope with the RFI levels found at the EVLA site. For the two lowest frequency bands, balanced amplifiers are necessary because wideband, low‐loss cooled isolators are not possible at these frequencies. In the last year, we successfully developed a two‐stage, balanced, low‐ noise amplifier optimized for the 2‐4 GHz band and built several production units for use in receiver prototyping. This amplifier uses an InP Northrup Grumman Space Technology (NGST) HFET in the first stage and a commercial pseudomorphic FHX45X (Fujitsu) device in the second stage to allow for a much higher third‐order intercept point of this amplifier and, consequently, better immunity to the effects of interference. We also developed a three‐stage amplifier covering 4‐8 GHz using InP HFETs. A paper design for an optimized amplifier for 8‐ 12 GHz has been completed. Also, a new version of the 4‐12 GHz amplifier has been developed and tested. This redesign was required as we have exhausted the supply of some of the devices from an older InP HFET wafer.

Figure 7.1. 2‐4 GHz balanced, two‐stage, low‐noise amplifier (top) and 4‐8 GHz three‐stage amplifier bottom) for the EVLA.

The unsurpassed performance of cryogenic amplifiers has been made possible by the use of the transistors developed under JPL leadership for its CHOP program, in particular, the wafer run known as “Cryo‐3.” We came to an agreement with JPL to buy into the CHOP program and thousands of devices are now in NRAO possession.

There was further work in the area of support for the Planck satellite team at Jodrell Bank to help with their amplifier development of the 40 GHz amplifier for Planck. Also, the Caltech

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CBI experiment has been supported with the final upgrade of their amplifiers with NGST/JPL Cryo‐3 devices to improve sensitivity for the search for the polarization characteristics of the CMBR.

An effort was made to review several problem amplifiers covering the 12‐18 GHz range. In a collaborative effort between Marian Pospieszalski (NRAO) and Edward Tong of the Harvard‐ Smithsonian Center for Astrophysics, one of these amplifiers was delivered to the Smithsonian Millimeter Array (SMA) for the evaluation of a very wide instantaneous bandwidth SIS mixer for the 360‐410 GHz band.

Production amplifiers were built for receiver systems on the GBT and VLA. The total number of amplifiers produced was 70. Table 7.1 lists current production amplifier models.

Table 7.1 Current NRAO Production Amplifiers Average Band Band Noise Comment (GHz) Name (K) 0.3‐0.4 2.0 Balanced 0.4‐0.5 2.0 Balanced 0.5‐0.7 2.0 Balanced 0.7‐0.9 3.0 Balanced 0.9‐1.2 3.0 Balanced 1.0‐2.0 L 4.0 Balanced, InP 2.0‐4.0 L/S 4.0 Balanced, InP 4.0‐8.0 S/C 3.5 InP 4‐12 S/C/X 5 InP 8‐18 X/Ku 7 InP 18‐26.5 K 9 InP 26.5‐40 Ka 10 InP 36‐50 Q 13 InP 65‐90 V 45 InP 70‐115 W 50 InP

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Planned Activities for FY 2006

The design of the 4‐8 GHz amplifier will be further refined and the already designed 8‐12 GHz amplifier will be prototyped and put into production. Also, the current 8‐18 GHz amplifier will be redesigned and a 12‐18 GHz amplifier will be developed for the EVLA. We will refine the designs of the 26.5‐40 and 40‐50 GHz amplifiers to optimize overall receiver noise performance for precisely these bands.

If time permits, new 60‐90 GHz and 75‐115 GHz designs will be developed. These designs will use devices from the NGST/JPL Cryo‐3 wafer as the supply of devices with which the previous designs were built is nearly exhausted.

Amplifier construction will continue at a rate sufficient to keep up with the needs of the EVLA and GBT.

We anticipate that, for frequencies below 12 GHz, it will be possible to outsource the amplifier assembly so that we do not have to add to the amplifier technician pool. There has been some success in this area for ALMA IF preamplifiers. However, we will continue to perform the cryogenic testing since this function is not available commercially. Construction of amplifiers for 12 GHz and above will likely continue as an in‐house activity during FY 2006, although we will investigate contractor assembly for the higher frequencies as a possible alternative based on the experience gained at lower frequencies.

MMIC Development

Monolithic Millimeter‐Wave Integrated Circuits (MMICs) provide highly‐repeatable performance in a more compact package than traditional millimeter‐wave assemblies, and at lower cost in large quantities. This dramatically improves the tradeoff between cost and performance in array architectures. NRAO engineers are continuing the development of MMICs and MMIC‐based subsystems for the current and next generation of centimeter and millimeter‐wave radio astronomy receivers and arrays. For example, key components such as custom MMIC power amplifiers, multipliers, and mixers have been developed for the ALMA local oscillator (LO) system. We have also developed a MMIC‐based prototype Compact Water Vapor Radiometer (CWVR) for the EVLA.

As the cost of GaAs and InP wafer runs is quite high, we will continue to exploit opportunities to share a mask set and wafer run with collaborators. There will be several opportunities to do so in the next year. While these wafer runs are necessary to complete receiver components for

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existing projects such as ALMA and the EVLA, they are also the perfect opportunity to prototype new experimental designs for future upgrades and applications.

Accomplishments in FY 2005

In FY 2005, new MMIC designs and modules have included:

• A wideband MMIC LNA for the 11‐34 GHz SKA band (see Figure 7.2). • A revised version of the 2‐4 GHz gain slope equalizer. • A MMIC‐based prototype Compact Water Vapor Radiometer (CWVR) for the EVLA. • Second‐iteration multiplier and mixer designs for the ALMA Active Multiplier Chains (AMCs). • Revised W‐Band power amplifier MMICs for improved performance in the existing ALMA LO bands, and two new PA designs to meet the demanding requirements of the ALMA‐J Bands 4 and 8.

Planned Activities for FY 2006

Plans for future developments include:

• Preliminary PA designs for ALMA Band 10. • Revision of the CWVR module for the EVLA. • Revision of the SKA wideband LNA in Figure 1 by taking advantage of a shared wafer run opportunity with NGST this fall.

Other potential MMIC research areas include decade‐bandwidth components, the integration of low‐noise amplifiers with antenna structures, and large‐dynamic range module designs for future arrays such as FASR.

Figure 7.2. The 11‐34 GHz low‐noise amplifier. The chip was fabricated by Northrop Grumman Space Technology in their 0.1 µm InP pHEMT MMIC process. Chip dimensions are 2000 x 730 x 75 µm.

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Millimeter‐Wave Receiver Development

In addition to the ALMA 211‐275 GHz receiver development work reported in Chapter 3 , three millimeter and sub‐millimeter technical development efforts are currently being carried out at the CDL development of a new SIS mixer design for 385‐500 GHz, development of a Hot Electron Bolometer (HEB) mixer for 600‐720 GHz, and a new technology development effort for 350‐μm (780‐950) GHz heterodyne receivers.

Accomplishments in FY 2005

385‐500 GHz SIS mixer. This is a joint Research and Development (R&D) project between CDL and the University of Virginia Microfabrication Laboratory (UVML), and is supported mainly by an NSF grant to UVA. The objective of this effort is to demonstrate the new beam lead Silicon on Insulator (SOI) substrate SIS mixer technology for the 385‐500 GHz band (which is also ALMA Band 8) which will provide wideband tunerless operation with noise (measured in photons) comparable to ALMA Band 6, and which can be manufactured by the highly‐ repeatable processes available at the UVA foundry.

We have carried out a complete redesign of the 385‐500 GHz mixer circuit in FY 2005. This redesign uses UVA’s new 3‐μm SOI substrate technology which offers several advantages over the old 7‐μm SOI process. The 3‐μm substrate is more transparent than the 7‐μm substrate, making it easier to align the features on the back of the substrate with the pattern on the front, and requires a shorter RIE each time to define the final chip size. Two new mixer circuits have been developed: the first uses the microstrip self‐inductance of the array as the main tuning element, and the second uses a new two‐junction tuning configuration. The mask set for the mixer is being fabricated by e‐beam lithography at a commercial mask manufacturer. The junction fabrication process is being optimized at UVML.

HEB mixers. This beam lead HEB mixer work is a continuation of a Small Grant for Exploratory Research awarded by the NSF under the Approaches to Combat Terrorism program. In the last year, with the assistance of two NSF REU students, a phonon‐cooled HEB (pHEB) fabricated on 3 m Silicon (SOI) by the Microfabrication Laboratory at the University of Virginia (UVML) has been characterized. The 500 K receiver noise temperature measured with this mixer compares favorably with the state‐of‐the‐art for HEB mixers at 660 GHz. These results verify the mixer performance of the SOI processing techniques, allowing for further design and integration of SOI pHEB mixers in receivers operating above 1 THz. IF measurements have been made up to 3.9 GHz so far with little noise increase recorded. A Research Experience for Undergraduates (REU) student is currently measuring the HEB mixer with an ALMA‐type 4‐12 GHz IF LNA.

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Figure 7.3 illustrates the inside of the phonon‐cooled HEB mixer block. The diagonal horn feed for the RF and LO flares out to the right. Integrated beam leads are used to suspend the SOI chip in the channel, make the ground connection (at top), and connect the IF to the microstrip line (at bottom).

Figure 7.3. Photograph of inside of 660 GHz phonon‐cooled HEB mixer.

350‐μm (780‐950) GHz Heterodyne Receiver Technology Development. The 350‐μm atmospheric window (780‐950 GHz) is important for the next generation of terrestrial radio telescopes as well as for satellite instruments. At present, no heterodyne receivers for this band can achieve the nearly quantum‐limited sensitivity of niobium SIS receivers below ~ 600 GHz. In addition, there are two more important reasons for the CDL to undertake this development effort: (i) success in this work will put NRAO in a strong position to bid on the ALMA Band 10 receiver production, and (ii) this project will provide bridging funds to keep millimeter‐wave receiver development alive at NRAO and UVA between the end of the ALMA development phase and the beginning of its operation phase in about three years when funds are expected to be available to support further receiver development. The CDL is, therefore, proposing to develop the technology for quantum‐limited receivers in this band. The goal is to produce reliable, inexpensive, quantum‐limited receivers using recently‐developed SIS mixer fabrication

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technology. This proposal has been approved by the Director. Funds have been earmarked for this project which has recently been approved by NSF.

Planned Activities for FY 2006

385‐500 GHz SIS mixer. Optimization of the junction fabrication process will be completed and a wafer will be fabricated. A mixer block will be designed and the mixer performance will be evaluated.

HEB mixer. Diffusion‐cooled HEB mixers at 600 GHz will be characterized and compared to the pHEB mixer already characterized. A SOI beam lead HEB mixer will be designed for 1.2‐1.6 THz operation, covering the highest‐frequency atmospheric windows at the Atacama site.

350‐μm (780‐950) GHz Heterodyne Receiver Technology Development. The mixer design work will start immediately upon receipt of funds. The mixers will be designed to support a wide IF bandwidth, which is desirable for both spectral line and continuum measurements, and in a form suitable for sideband‐separating and balanced mixers. Optimization of the junction fabrication process will be carried out at the UVML. The current SIS mixer test setup will be retrofitted and upgraded for this new frequency band (780‐950 GHz).

Balanced SIS Mixer Development. This is a new initiative which will be supported primarily by University of Arizona (UAz) funds. NRAOʹs role in this UAz project is to develop a single‐chip IF 180‐degree hybrid with wide bandwidth (4‐12 GHz) and a prototype 230 GHz balanced SIS mixer. The IF hybrid will solve the problem of combining the two IF outputs of a balanced mixer with appropriate phasing and impedance level over a wide bandwidth. It will operate with balanced SIS mixers in any RF band, and give all the advantages of a balanced mixer (lower LO power, suppression of LO noise) with wide IF bandwidth. Balanced sideband‐separating SIS mixers will be practical using such an IF hybrid

Electromagnetics

Due to the recent advance in the development of wideband amplifiers and mixers, the bandwidth of new generation receiving systems is no longer limited solely by these active components but also by passive components such as the feed, phase shifter, and orthomode transducer in the receiving system. We have designed and tested several new components with the goal of having receiver performance limited only by the bandwidth of single‐mode waveguide at high frequencies and by feed dimensions at the low‐frequency end of the spectrum.

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Accomplishments in FY 2005

A substantial amount of work was done on the design of feeds and supporting elements for the EVLA:

• A prototype of the 4‐8 GHz feed for the EVLA was built and measured. The measurement results agree well with theory. The feed has been installed on the first EVLA test antenna and measured efficiency varies between 0.55 and 0.65. The spillover is nearly constant at 6 K from zenith to 20º elevation and then increases rapidly at lower elevations of the antenna. • A prototype of the 8‐12 GHz feed for the EVLA was designed, built and measured. Its performance compares well with simulations. It has very low cross‐polar sidelobes and excellent match at the input. • Analysis of the antenna aperture efficiency and spillover using measured feed patterns of the L‐band feed was completed to explain the results of measurements done on an EVLA antenna. Aperture efficiency was also computed for the 4‐8 GHz band. • A comparison study of the performances of a profile horn and a linear taper horn of the same size in the 2‐4 GHz band was completed. This study was performed to determine if the high spillover at lower elevation angles of the antenna for the profile horn could be reduced by using a linear taper horn. • The EVLA Q‐band feed was measured by itself, and also with the feed installed inside an interface tube that mounts to the antenna. The tube changes the taper of the feed very little, and this will not have any significant effect on the aperture efficiency.

Planned Activities for FY 2006

• Work will continue on the design and testing of 2‐4 and 12‐18 GHz feeds. Polarizers for the 8‐12 and 12‐18 GHz bands will be designed and tested. • A dual‐frequency 300/600 MHz prime focus feed for the GBT will be developed. • The sidelobe characteristics of the GBT will be studied, then a 1.30‐1.45 GHz prime focus feed will be designed to provide a lower system temperature and a cleaner beam compared to that with a secondary focus feed. • A corrugated phase shifter for the 90‐115 GHz band will be developed.

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Green Bank Solar Radio Burst Spectrometer (GB/SRBS)

In June 2003, the NRAO received an NSF MRI grant to develop a high‐performance instrument to receive solar radio emissions with adequate temporal and spectral resolution to probe a wide variety of active solar phenomena from the base of the corona, including energy released from flares, particle acceleration, and escape, coronal shocks, and electron beams. The instrument, known as the Green Bank Solar Radio Burst Spectrometer (GB/SRBS), actually consists of two radio spectrometers that will together provide contiguous frequency coverage from 10‐2500 MHz. This instrument provides a basic research tool in solar radiophysics for use by the wider community, remedies the lack of an important component of the U.S. Space Weather effort, and provides a platform for research and development work on broadband antennas, feeds, and receivers needed for the upcoming Frequency‐Agile Solar Radiotelescope (FASR) project.

This instrument will be developed in three phases so that it may begin contributing toward the science objectives very early in the project schedule and then build upon learned techniques and procedures. Phase I is a low‐frequency, single‐polarization system; Phase II provides broadband, dual‐polarization spectral coverage through use of the Green Bank 45‐foot radio telescope; and Phase III improves frequency agility and time resolution through the application of a unique hybrid analog‐digital spectrometer design. The data from this instrument are being archived and are available at the project website (http://www.nrao.edu/astrores/gbsrbs/). In addition, REU and graduate students have made and will continue to make significant contributions to this project.

Accomplishments

The Phase I system (20‐70 MHz, single polarization) was deployed in Green Bank in January 2004, and it has been in continuous operation ever since with excellent reliability. The antenna was adopted from the original dipole design for the Long Wavelength Array (LWA). CDL development activities included the overall system design, a high‐dynamic range, low‐noise active balun, and software needed to calibrate and control a sweep‐type spectrometer having 30 kHz frequency resolution.

The high‐frequency component of Phase II (beginning with 300‐1000 MHz, dual polarization) was deployed on the Green Bank 45‐foot radio telescope in June 2005. CDL development activities included the overall system design; a 10:1 bandwidth feed (300‐3000 MHz); a feed‐ mounted, low‐noise active balun (300‐3000 MHz); a receiver system; and a dual‐channel, sweep‐ type spectrometer. Initial results are showing excellent receiver stability and sensitivity. In addition, the medium frequency component of Phase II (70‐300 MHz) has been developed and is currently being fabricated. It will be developed in September 2005.

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The Phase III system has also been designed. The system consists of several independent receivers with associated data acquisition systems. Each analog receiver amplifies, filters, and translates a 20 MHz segment of the radio frequency band down to baseband where it is sampled, Fourier‐transformed, and stored. The entire radio frequency band is covered by step‐ tuning the local oscillator. Several such systems will operate in parallel, allowing improved time resolution together with a high degree of system reconfigurability. Modules for the Phase III system have already been prototyped. These include the data acquisition board and associated spectrometer software, as well as the frequency converter boards.

Planned Activities for FY 2006

Work will continue on the development of the Phase III spectrometer with deployment scheduled for mid‐2006. The remainder of the high‐frequency band, namely 1000‐3000 MHz, will be implemented. In addition, we plan to replace the LWA prototype antenna with a suite of scaled, dual‐polarized, sleeved dipoles to improve the sensitivity in the 10‐70 MHz band.

We are also planning to explore various broadband feed designs that incorporate integrated low‐noise active baluns. Prototypes of these designs will be fabricated at the CDL and evaluated on the 45‐foot radio telescope. These prototypes will also be evaluated for possible use on the FASR array being planned for the future.

Figure 7.4. Photograph of the 300‐3000 MHz broadband feed with integrated amplifier. The dual‐polarized feed structure is a pyramidal‐style, log‐periodic array with trapezoidal elements. The amplifier, located at the apex of the pyramid, is an active balun circuit using commercially‐available MMICs.

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Introduction

In mid‐2003 the Division of Science and Academic Affairs (DSAA) was created at the NRAO. The purpose of this division is to provide a more coherent framework for the scientific and academic activities of the Observatory and especially to facilitate interactions with the U.S. university astronomy community. Special emphasis is placed on the stimulation of scientific research throughout the NRAO sites.

A number of committees are coordinated by the DSAA, including the Observatory Science Council, a committee to advise the director of NRAO on scientific issues, the Astronomy Performance Review Committee (APRC, chaired by Frazer Owen) and the Scientist Performance Review Committee (SPRC, chaired by Anthony Kerr).

The Division’s activities also include the coordination of NRAO‐sponsored conferences and the planning of joint university‐NRAO meetings, the coordination of external proposals originating from the NRAO scientific staff, and the introduction of NRAO‐wide colloquia. The Division assists in the assignment of telescope time, helping to insure that NRAO facilities are used in the best possible way to advance science and astronomy.

The Research Staff of the NRAO

The research staff comprises scientists with experience in different aspects of astronomy and astrophysics, in computer sciences, and in electronic instrumentation. A fraction of the time of each of the research staff is spent on personal research. By maintaining an active research interest, the scientist keeps abreast of the developments in her or his field of specialty, and is better able to maintain contacts with the broader user community. A fraction of the scientists’ time is spent in direct support of Observatory programs. In addition a fraction of the time is devoted to service to the broader astronomical community, coordinating planning for new instrumentation, serving on review panels, and providing referee evaluations for publications and grant proposals. This division of effort is analogous to that of university faculty who devote time to research, teaching, university affairs, and external service.

The scientific programs which are planned by the staff for FY 2005 are summarized in Appendix A. The members of the research staff are listed in Appendix B. The major fields of astronomical and astrophysical research are well represented; many of the staff have strong backgrounds in radio‐astronomical techniques.

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Science Support

The support needed by the Observatory spans a wide range of functions. A demanding task is the continuing commissioning of the Green Bank Telescope (GBT). A number of staff have and will remain active in tests of the high‐frequency performance of the GBT. Operating telescopes require scientific support throughout their effective life‐times. Each system needs continuing assessment of its performance, and scientific involvement is important as upgrades are designed, developed, and implemented.

The scientific staff also provides assistance to visiting observers, since the latter frequently have experience at other wavelengths and need an introduction to radio‐astronomy instrumentation. One component of this endeavor is assistance to visiting observers in the planning of new observations and in the analysis of the telescope data. In addition, the NRAO conducts orientation workshops in interferometry and, with the Arecibo Observatory, in single‐dish radio techniques. In each case the scientific staff serve as the faculty of the school. In summer 2003 the single‐dish summer school was held at Arecibo, and the interferometry summer school was held in Socorro in June 2004.

New Initiatives

A major role of the scientific staff is to help define and to implement new instrumentation and new facilities for radio astronomy. These activities include initiatives generated internally within NRAO as well as projects developed externally or jointly between NRAO staff members and the wider national and international community. During the next year and beyond, the scientific staff will continue to be involved in the ALMA and EVLA construction projects as well as planning for their operational phase, in particular to define the role of the North American ALMA Science Center (NAASC).

A number of NRAO scientific staff members are actively involved in the planning at the national and especially international level for the Square Kilometer Array with leadership roles in both defining the scientific goals as well as addressing the formidable technical and organizational challenges for this planned large international facility. Members of the scientific staff are also working with colleagues in the newly formed Southwest Consortium and the University of New Mexico to facilitate their development of a Long Wavelength Array (LWA) and the coordination of the LWA with NRAO activities in New Mexico. Planning for FASR, the Frequency Agile Solar Radio telescope, continues as a joint effort of NRAO and university scientists. Discussions between NRAO scientists and Japanese and Russian scientists to implement space VLBI facilities are ongoing. Smaller scientific staff programs to develop Focal Plane Arrays and research on RFI Mitigation will also continue in close collaboration with similar activities at other institutions.

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Maintaining Association with the Scientific Community

The NRAO staff serves as a conduit by which the scientific community can maintain its connection to the NRAO. Staff personnel serve on advisory committees and review panels, serve as editors for professional journals, give colloquia and invited talks, and attend meetings and workshops on a variety of topics. In these activities there is an opportunity for the external scientists to discuss with their NRAO colleagues the state of current instrumentation, the direction of current research, and the need for new techniques and instrumentation.

Library and Archives Library

The primary mission of the NRAO Library is to provide research support for the explorations of scientists, engineers, and students in the field of astronomy and the information needs of all NRAO staff. Since the Observatory is a national facility, the NRAO Library serves the wider astronomical community. This support is provided through collection and delivery of astronomical and supporting literature.

The collection is made available through national and international library lending and via individual requests.

The NRAO Library staff and collections are located in Charlottesville, Green Bank, and Socorro.

The arrival of the new Observatory Librarian in February 2005, completion of renovation at Charlottesville in March, the April return of the Charlottesville collection from storage, and the closing of the Tucson Library location in May, provided an opportunity to look forward.

The future of the NRAO Library is dictated by the demands placed on the Library. These are:

• easy availability of current and historical information for scientists and engineers at NRAO, and • the ability to readily identify and locate NRAO publications by the larger astronomical community.

To ensure responsive growth in these areas, the NRAO Library will emphasize:

• collection development and maintenance, and point‐of‐access for holdings and information; • streamlining acquisitions, processing, data gathering, and reports processing.

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As an initial effort to begin responsive growth, the Observatory Librarian and the ESO Librarian in Munich are working together to define and identify the collection needed to support ALMA.

To serve our diverse and distant community in a timely manner, the NRAO Library Web Page was updated. Web page improvements will continue to keep pace with our community and electronic delivery advances.

The collections at Charlottesville, Green Bank, and Socorro are undergoing bar coding to help collection maintenance, inventory, and ease of loaning.

NRAO Archives

The intent of the NRAO Archives is to actively seek out, collect, organize, and preserve institutional records and personal papers of enduring value which document NRAO’s historical development, institutional history, instrument construction, and ongoing activities, including its participation in multi‐institutional collaborations. As the national facility for radio astronomy, it also is appropriate for the Archives to include materials on history and development of radio astronomy in the United States, particularly if such materials are in danger of being lost or discarded by other institutions or individuals.

During FY 2005, the Archives moved into dedicated space in the Edgemont Road addition, the Web pages chronicling Doc Ewen’s recollections of detection of the HI line and of U.S. radio astronomy history were completed, processing began on Reber materials previously housed in Green Bank, and processing began on the John Findlay and Director’s Office files in the Edgemont Road penthouse. The Archives received a significant gift with the donation of the extensive papers of John Kraus by his son, the estate executor.

We expect to receive from Reber’s estate the significant portion of his correspondence and papers he had retained in Tasmania, and in FY 2006 will continue working on Reber materials. We will begin processing the John Kraus papers, and work will continue on processing Findlay and Director’s Office material. We will begin putting data into Web‐based finding aids that will allow researchers, both within and outside NRAO, to search indexes to the processed portions of the Archives collection.

The Archives will be actively involved in planning exhibits for NRAO’s 5tenth anniversary celebration in October 2006.

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Educational Programs

Undergraduate Research Program

Summer 2005 marks the forty‐sixth year of the NRAO Summer Student Program. This program supports approximately 30 undergraduate and graduate students for 10‐12 weeks each summer at one of the three NRAO sites in New Mexico, West Virginia, and Virginia. The students are supervised by an NRAO staff member on a research project in the supervisor’s area of expertise. The project may involve any aspect of astronomy, including original research, instrumentation, telescope design and engineering, or astronomical software development. In addition to their research project, students take part in a summer lecture series, field trips to other astronomical observatory sites, and collaborate on an observing project using an NRAO radio telescope. The students contribute materially to the research they are assigned, and these contributions are often reflected in co‐authorship on resulting papers. At the end of the summer, students give oral presentations to the local NRAO staff and submit written reports. A majority of the students receive financial support from the NRAO to attend the American Astronomical Society winter meeting to present posters on their research projects.

In summer 2006, approximately fifteen undergraduate astronomy students will be supported via the NSF‐funded Research Experiences for Undergraduates (REU) program, with an additional fifteen REU‐ineligible students (graduating seniors, graduate and foreign students) funded out of the NRAO operations.

The NRAO has also established a co‐op program wherein undergraduate engineering students from participating institutions work at one of the NRAO sites for two (non‐consecutive) semesters. The program allows students to acquire important technical skills by working under the supervision of the NRAO technical staff on problems at the technological forefront. The program is presently funded through the NSF Cooperative Agreement.

Graduate Education

Professional astrophysics is a multi‐wavelength problem‐oriented discipline. Students entering the field need a wider range of skills than most college courses provide. To rectify this situation, and to train students in the techniques of radio astronomy specifically required for the individual student’s research, two programs are available at the NRAO. First, summer‐student positions for graduating seniors and first‐and second‐year graduate students are available (as described above). They allow students to gain experience in radio astronomical research early in their graduate careers, and to establish important skills as they embark on their thesis research as described above. Second, NRAO staff scientists collaborate with university astronomers in the supervision of Ph.D. thesis projects. Awards, typically of two years

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duration, are made to graduate students for residence at the appropriate NRAO sites, acquiring data, reducing it, and writing their thesis all under NRAO guidance. This program is highly valued by faculty in universities unable to support this kind of position otherwise, and by NRAO staff for the excellent student interaction it generates.

In addition to graduate summer students and resident graduate students, more than 100 Ph.D. students make observations with NRAO telescopes each year. Short stays of one to three weeks at the site, travel reimbursement, and computing facilities are provided to assist students using NRAO facilities.

In 2002 the NRAO instituted a program to provide financial support to students performing research programs on the GBT. Graduate or undergraduate students at U.S. universities are eligible for the program. The primary objective of the program is to foster the training of a new generation of telescope users. The program is designed for one‐year research projects, although two‐year thesis projects may be considered. The funding cap per student is $35,000, which includes the direct stipend for student support, miscellaneous expenses such as computers and travel, and up to $3000 to offset the cost of administering the program at the university.

The Financial Support program continues to receive a strong response. Since its inception, thirty five support stipends have been awarded to twenty six individual students. In FY 2005 eight students received awards, and approximately $345,000 was expended from Observatory operational funds toward this program. We anticipate a program of similar size in FY 2006.

Jansky Fellowships

Postdoctoral astronomers are given Jansky Fellow positions with a term of two years that may be extended for a third year. In the selection process, recent graduates are given preference over those applying for a second postdoctoral position. Jansky research‐associate appointments are available not only to radio astronomy students but also to recent Ph.D. recipients in engineering and computer science. Jansky Fellows formulate and carry out investigations independently or in collaboration with others within the wide framework of interests of the Observatory.

The Janksy Postdoctoral Fellowship Program remains one of the elite postdoctoral fellowship programs in the world, including resident and non‐resident fellows. The 2005 non‐resident Jansky Fellows and their host institutions are: A. Baker (University of Maryland), S. Chatterjee (CfA), T. Cheung (Stanford), N. Miller (Johns Hopkins University), K. Spekkens (Rutgers), J. Aguirre (Colorado), and M. Haverkorn (Berkeley). The resident fellows are: V. Fish, N. Kanekar, J.‐P. Macquart, D. Meier (Socorro), Y. Kovalev (GB), and P. Chandra, who will split her time between U. Virginia and NRAO/CV. All Fellows were selected by a committee of scientists from external U.S. research institutions and from the NRAO. Both resident and non‐

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resident Fellows include discretionary research budgets. An annual Jansky symposium is held at the NRAO to foster interaction among the Fellows and the NRAO staff. The Jansky Fellowship program is intended to prepare the Jansky Fellows for leadership positions in the U.S. astronomical community and to promote the health of radio astronomy in the U.S. An annual review is held to evaluate the progress of the Fellows. In 2006 we expect to appoint between four and six new Fellows.

Visitor Program

The NRAO encourages Ph.D. scientists and engineers in radio astronomy and related fields to visit any of its sites. We particularly encourage visits by young scientists who are faculty members at colleges and universities, scientists affiliated with NASA missions, foreign scientists, and senior scientists. The terms of a visit are negotiable, ranging in duration from weeks to months. The purpose of the visit can be for interaction with one or more NRAO staff members, summer visits for research, or sabbatical visits.

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9. Observatory Software

Overview

In recent years, ``Data Managementʹʹ at the NRAO has undergone a transition from being largely observatory‐based to largely project‐based with a high level of cooperation among the projects. During the past year, a common high‐level architecture for the ``end‐to‐endʹʹ features of the observatoryʹs instruments (user visible aspects of the telescope) has been developed by a group of the designers from the major NRAO instruments and the Atacama Large Millimeter Array (ALMA). The common high‐level design should facilitate sharing of software and operational expertise among the various instruments. Each project is responsible for adapting this plan to its instrument.

There has been substantial development over the last year. The Green Bank Telescope (GBT) has new observation control software that is more suitable for automated observing, and the GBTIDL package has been released for analyzing GBT spectroscopic data. The NRAO Proposal Submission Tool, developed at the Array Operations Center, (AOC), has been successfully used for the June 1, 2005 GBT proposal deadline. The NRAO on‐line archive is proving very popular and is now the principle means of distributing Very Large Array (VLA) data. Roughly half the requests from the archive are for public domain (non‐PI) data. The NRAO archive has been expanding its services to the Virtual Observatory.

Project‐Based Software Development

Green Bank Telescope

GBT software work encompasses monitor and control of existing and new instrumentation, observing systems development, and data analysis development. Development for the latter two categories requires consideration of Observatory‐wide software strategies. Because no GBT software resources are available to be dedicated to Observatory‐wide (e2e) software development, all new GBT software developments have been undertaken with the overall strategy in mind. Opportunities for synergy (where satisfying an Observatory‐wide need will simultaneously help meet GBT project goals or improve its operational efficiency) have been aggressively pursued.

Observatory‐wide related GBT software work in 2005 and 2006 is being focused on improving the effectiveness of dynamic scheduling and remote observing. This includes: (a) reliably archiving the raw data in a format that conforms to an acceptable science data model (which will also accommodate the WCS and new instrumentation being commissioned in 2006‐2007); (b) ensuring that recommended calibration strategies are in place for all of the standard observing modes, and that these are utilized in quick‐look data processing; (c) producing

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reference spectra/reference images as they become available; and (d) producing and archiving observation meta‐data and quality information. The final task involves reconciling plans for the observation management and scheduling databases in Green Bank with the new user database resident in Socorro. This will ensure that information across NRAO sites is not duplicated, which will ultimately preserve data integrity.

In support of these goals, work was started on a science data model as part of developing the GBTIDL product. By integrating this work with established quick look display work, reference images will be generated by early 2006. Analysis work was also launched for calibration and dynamic scheduling projects.

Additional detail on GBT observing software and data analysis software development plans in FY 2006 are described in the GBT portion of the NRAO Facilities chapter (section 6).

EVLA e2e Software

The purpose of Expanded Very Large Array (EVLA) e2e software is to seamlessly connect all of the various software components involved with the EVLA and ultimately to connect all parts of observing with the EVLA from the user and observatory perspective. Formally, this includes at least the following components:

• Proposal preparation, submission and handling; • Observation preparation; • Observation scheduling; • Real‐time operations (M&C); • Data capture and format (DCAF); • Telescope calibration (TelCal); • Observation monitoring; • Archive storage, search, and retrieval; • Data reduction pipelines ‐ calibration, quick‐look, and image; • Post‐processing.

Because it is clear that in most of these areas the EVLA Computing Division does not have enough resources to complete the work itself, borrowing from ALMA will be a key element of EVLA e2e software. Much of the discussion below will be centered on that topic, describing various activities to ensure that this collaboration and borrowing can be carried out successfully.

In addition, the development of EVLA e2e software is based heavily on prototypes that are built for the VLA. This affords an opportunity to test designs and prototypes on a functioning interferometer. This prototyping effort will also be discussed below.

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The EVLA Computing Division consists of seventeen employees, including management. Seven of these employees are directly tasked with supporting M&C software. Seven are available for e2e work (of which two are newly created positions supported from EVLA contingency funds). Of these seven e2e employees, four are not available full time for EVLA work, but rather split their time between EVLA‐specific and NRAO‐wide e2e development. They are managed directly through the Interferometry Software Division (ISD). More details than are included here can be found in the EVLA Project Book in Chapters 9 and 11.

Requirements, Use Cases, and Delivery Dates

The full set of requirements documents was completed during 2004, and includes documents for: e2e; post‐processing; real‐time system; operations; engineering. These can be found on the EVLA Computing Documents website (Memos 26‐29, 38). These documents are intended to be living descriptions of the current requirements, and are updated periodically. Over the past few months, the priorities and dates given in the e2e requirements document have been revised.

Use cases have been written in the following areas:

• Continuum observing; • Polarization observing; • Spectral line observing; • User Database (UDB) interactions and administration.

A set of delivery dates for different levels of key subsystems for the EVLA e2e is shown in the table below:

Table 9.1. EVLA e2e Software Subsystem Delivery Dates Subsystem Initial Prototype Intermediate Full Tool Proposal Preparation C D E Observation Preparation C D E Observation Scheduling B D E Archive B C D Pipelines D E postE On‐line Calibration (TelCal) B C D Data Capture and Format (DCAF) A B C Observation Monitoring C D E Key: A. 2006 Q3 (Prototype Correlator) B. 2007 Q3 (Limited Production Correlator) C. 2008 Q2 (Shared‐Risk Observing) D. 2009 Q3 (Full correlator) E. 2010 Q4 (Full Science Operations)

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Overall Architecture

A high‐level design for all EVLA software was developed in the first half of 2004 and was reviewed by the NRAO e2e oversight committee in June 2004. The review was positive, and that design has been adopted. Key elements of the design include:

• Conformance to NRAO‐wide Archive, Project, Science Data, and Observatory Models; • Meets high‐level requirements as set out in the requirements documents; • Defines key subsystems, most of which are analogous to ALMA subsystems; • Defines highest level interactions and communication between subsystems.

It is clear that this high‐level design needs to be carried down to the next level‐producing detailed designs for each of the subsystems, and the interactions and communication between them. This effort is just about to begin, with the goal of completing the exercise by winter 2005/2006. A review will occur at that time.

Additional detail regarding the EVLA software plans are provided in section 5.

Proposal Preparation, Submission, and Handling

An NRAO‐wide Proposal Preparation and Submission Tool (PST) has been in development throughout 2004‐2005. The aim of the project is to develop a Web‐based proposal tool to be used eventually by all NRAO telescopes and projects. Negotiations with the equivalent ALMA IPT in April 2004 led to agreement on common architectural principles and implementation and these discussions continue.

After extensive internal testing, the GBT proposal deadline in June 2005 used this new tool exclusively. Reports from users of the tool were extremely positive. Support for the VLA will be added for the February 2006 proposal deadline. Support for the Very Long Baseline Array (VLBA) is intended to be added perhaps for the June 2006 proposal deadline.

Observation Preparation and Scheduling

The intent is to copy as much as possible of the ALMA software to do this. ALMA has split the ʺObsPrep Toolʺ into two elements: Phase I, which is essentially the PST described above; and Phase II, which is what has been called for EVLA the ʺObservation Preparation Toolʺ. The ALMA version of the Observation Preparation Tool will be adapted for use with the EVLA building on the experience gained from the equivalent VLA software.

Observations will use an adaptation of the ALMA ʺObservation Scheduling Toolʺ with the priority heuristics adapted to the EVLA case. This adaption is being used in testing of dynamic

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scheduling for the VLA. The initial test occurred during the move from B to CnB configuration in mid‐June 2005.

Data Archiving

The EVLA will be able to adopt much of the ALMA data archiving. This capability hinges critically on the adoption of a common Science Data Model. There has been significant collaboration with ALMA over the past year to ensure that the Science Data Model adopted for ALMA will be sufficient to support the EVLA, as well as the VLA and VLBA. Work on data archiving for the VLA is expected to be completed in fall 2005 reducing the dependence on the aging ModComp computers. Design of the EVLA data archiving system began in June 2005 and a complete design and early implementation are anticipated by the time the prototype correlator arrives in Q1 2007.

Observation Monitoring

The ability for operators to monitor on‐going observations is critical so that the way the status and health of the array can be ascertained, and problems identified. In addition, the ability for astronomers to monitor their observations is important if they are to change the observations while executing, which are requirements. The plan is that both of these types of monitoring will be the same, except the astronomer monitoring tool will have no ability to actually control what is happening (only monitor). Another interaction will have to take place to actually change observations mid‐stream. Initial versions of the operator GUIs which give a rudimentary ability to monitor the progress of observations with the EVLA antennas are currently being developed.

Archive Storage, Search, and Retrieval

This is another area where significant borrowing from ALMA should occur. ALMA will almost certainly adopt the NGAST software system for its archive (recommended at the ALMA Archive Review, though not formally adopted by the ALMA project yet). Previously there was concern that the proprietary NGAST software would be difficult to obtain and modify for EVLA purposes, but NGAST was recently made open‐source and this concern is therefore ameliorated.

In addition to use of NGAST and ALMA software for the Archive Tool, knowledge gained from the current NRAO Data Archive will be important in guiding implementation of the tool. It should also be noted that the EVLA requirements include conformance to NVO standards, and support of National Virtual Observatory (NVO) queries, which work will also have commonality with ALMA.

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AIPS

The December 31, 2004 version of AIPS was developed through 2004 and then frozen in late December. It was available for download (with optional daily updates) during development and the frozen version may now be downloaded. The new test version, December 31, 2005, was started in December 2004 and is available for download and update. A total of 1,276 unique IP addresses downloaded a copy of AIPS. Statistics of the distributions of AIPS are shown in Figure 9.1.

Figure 9.1. Statistics of the distribution of AIPS.

We have found that the FORTRAN compiler developed by IBM for MacIntosh systems generates code that is 50% faster than that produced by the GNU compilers. Unfortunately, the IBM compiler is moderately expensive. The Intel compiler for Linux has also been tested. It failed to work with aggressive optimization, but with a carefully chosen set of compilation options, it does produce code about 40% faster on Pentium IV chips than by the GNU compiler.

Steps are being taken to support greater use of pipeline and other procedures in AIPS. In particular, data editing software has been developed. Studies are now underway to determine how these tasks may be used in AIPSʹs VLA and VLBA data‐reduction pipelines, particularly in flagging calibration sources.

Models for the primary flux calibration sources are now provided with AIPS. The pipeline procedures for the VLA are being revised to use these models, and AIPS calibration software is being refined as well. In particular, VLBA phase referencing using multiple calibrators to map the direction‐dependency of phase error is now supported.

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The AIPS user manual, The Cook Book, in now available in HTML and PDF versions, in addition to the traditional PostScript version. The new forms provide full cross‐reference capability including using the web browser to examine cross‐linked user documentation files.

AIPS++

Since the reorganization of the AIPS++ effort in April 2003, most of the development in the AIPS++ project has been directed toward fulfilling core synthesis data reduction, imaging and analysis requirements for ALMA and the EVLA. A consolidated plan for this development available on the web at: http://projectoffice.aips2.nrao.edu. The ALMA detailed plan is at: http://almasw.hq.eso.org/almasw/bin/view/OFFLINE/DesignReviews (Plan and Compliance Matrix); additional EVLA planning information is available on the web at: https://wiki.nrao.edu/bin/view/ISD/Planning‐2004. There are currently 10.3 FTEs devoted to the AIPS++ project; this includes the data capture and ALMA Science Data Model efforts in addition to software development.

The AIPS++ code base is being transformed into CASA (Common Astronomy Software Applications) to allow its usage in an execution framework, currently under development, including binding of tasks to new user interfaces, particularly Python. The execution framework will allow both user interactive and script‐driven applications and the current toolkit will be used to create tasks as in traditional data reduction packages. The execution framework will support the ALMA Common Software (ACS) which is used in all parts of the ALMA software system.

Ongoing testing cycles monitor the robustness and performance of the software, and the functionality of the package is audited against the ALMA and EVLA scientific requirements during the development process. Four use cases have been evaluated by panels of external testers (single field interferometry, mosaic, combined single‐dish and synthesis imaging, and wide‐field imaging) and all testers successfully exercised the tests. Testing suggests that AIPS++ speed is now comparable to Gildas and AIPS for ALMA scale problems and is approaching a factor of two of Miriad performance. For wide‐field EVLA imaging applications, implementation of new algorithms (e.g. W‐projection) in AIPS++ has provided significant improvements in speed over the previous generation of imaging algorithms used in other packages, as demonstrated in recent EVLA testing. Detailed test information and reports are available at the project office page given above; an ALMA Test Summary is available at: http://almasw.hq.eso.org/almasw/pub/Usertests/WebHome/test.summary.jul05.pdf

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Software Task Execution

NRAO is collaborating with the development of a task execution environment by the EU‐ funded RadioNet project. This scripting and task execution environment, ParselTongue, is a python‐based system with data access and remote execution capabilities. The initial implementation is for scripting of Classic AIPS tasks but it could be used for any software system based on a similar task/parameter model. This software is suitable for developing pipelines

Data Storage and Retrieval

Science Data Model (ALMA/VLA/VLBA)

The Science Data Model (SDM) is a logical structure for astronomical data. The concept first developed from the need for a data archival format for ALMA. Here, the concerns are mostly efficient storage of the basic data, with appropriate links to the observing proposal, observing parameters, monitor and control data points, and on‐line calibration results. To generalize this ALMA ʹarchiveʹ format to the VLA, EVLA, and VLBA use, it was clear that a more general concept, not tied primarily to ALMA archival data but also supporting the off‐line calibrations and data products, was needed.

The ALMA group generalized the ALMA archival data base to a more logical form. Additional items and a more general structure were added to incorporate the other NRAO arrays. For example, calibration table structures were added to support off‐line data reduction within the SDM, astrometric information was included, more general on‐line phase calibration signals and links to images were provided. The detailed incorporation of single‐dish astronomical observations is currently being investigated. The single dish and interferometry models are sufficiently different so that forcing both into one general SDM is not practical, although the general structures should be similar for data exchange and combination.

The SDM formulation and implementation are being tested through the use of simulated ALMA data that include virtually all the expected monitor and control signals and interferometer data. The incorporation of a complex VLBA data set (dual frequency, many channels, two subarrays) will also provide a good test of the functionality and completeness of the SDM.

It is expected that the SDM design will be an aid for the more uniform and ease of interchange of data and images among different observatories and telescopes, the NVO, and software data and imaging packages. A final draft of the SDM is expected by the end of 2005.

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Data Archive

The NRAO Data Archive has been operational since October 15, 2003 and allows everyone on‐ line access to all VLA data and some VLBA and GBT data (http://archive.nrao.edu/archive). To date, over 700 users from 250 institutions have downloaded over 4 Tbytes of telescope data (25,000 data files). The download data rate has climbed to about 200 Gbytes per month (1,600 data files per month). Data files over one year old are in the public domain and account for over one‐half of the download volume. The data files reside on a hard disk array and provide the archive users with fast access and downloads via FTP and HTTP. The archive access is illustrated in Figure 9.2.

Figure 9.2. Data volume downloaded as of July 26, 2005. Top line is total VLA + VLBA, just under 3.8 TBytes. The ʹxʹ line is VLA public data downloads, the squares are VLA proprietary data downloads. The time axis begins at October 15, 2003 and covers 2.75 years.

Currently the archive contains all VLA data going back to 1976, raw VLBA data going back to September 1999, and some calibrated VLBA data going back to October 1999. Efforts to expand the VLBA archive back to 1992 are underway and should be complete by the end of 2005. GBT data from July 2002 through October 2004 are available. During the third quarter of 2005 we will bring the archived GBT dataset up‐to‐date with the GBT dataset at Green Bank. By the end of 2005, we expect the archive to be over 25 TBytes in size. The sky coverage of VLA data in the archive is represented in Figure 9.3.

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Figure 9.3. All‐sky exposure map of the data in the on‐line VLA archive, averages over each square degree in the sky. Dark regions have total integration times of less than 300 seconds. The Galactic Plane and (surprisingly) the Ecliptic Plane show up prominently in this representation of historical VLA observing.

The Observatory is in the process of constructing and loading an archive mirror‐site at the National Center for Supercomputing Applications (NCSA). All VLA archival data have been transported to NCSA, and the daily VLA data files are transmitted to the NCSA via the Internet. All GBT data in the archive at the AOC are also archived at the NCSA. VLBA archival data is being transported to the NCSA archive at the rate of about 1 TByte per month. In the third quarter of 2005, we intend to offer data download services from the NCSA. This will take advantage of the NCSA high internet bandwidth and relieve the internet congestion at the Socorro‐AOC.

An NRAO Virtual Observatory Plan has been written and near‐term, mid‐term, and far‐term goals have been identified. In the near‐term we will identify and select processed data products to include in the archive and make available through VO services. In the beginning, these data products will mostly consist of images from NRAO surveys and large proposed observing projects. During the second quarter of 2005 we have made some progress on our near‐term VO goals. Currently over 30,000 images from the NVSS and FIRST surveys are loaded and cataloged in the archive. A VO Simple Image Access (SIA) service has been constructed for the NRAO Image Archive and is under final testing. We expect the NRAO SIA service will be operational in the third quarter of 2005.

In the future we expect the NRAO Science Data Archive to evolve into the Future NRAO Archive. The archival system that supports the EVLA, GBT, and VLBA will be integrated with the ALMA Science Data Archive which will reside at the North American ALMA Science Center in Charlottesville, Virginia. The Future NRAO Archive and the ALMA Science Data

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Archive will share hardware and software technology, and the two archive systems, although physically separate, will appear to scientific users as a single archival system.

Within the next year, the NRAO Science Data Archive becomes more integrated into emerging e2e systems, primarily the Proposal Tool and User Database Tool. We also expect to begin acquiring and implementing the ALMA‐ESO archive technology in the form of NGAS hardware modules and especially the NGAS software technology. We hope to ʹbreak the iceʹ on NGAS at the AOC by the end of 2005. VLA, VLBA and GBT data acquired beginning in 2006 should be archived in NGAS modules at the AOC.

Virtual Observatory (VO)

NRAO is a partner is both the U.S. National Virtual Observatory (NVO) and in the International Virtual Observatory Alliance (IVOA). NRAO is active in VO development on three fronts: (1) Participation in development of the international VO framework (e.g., science data access and FITS standards development); (2) providing radio data and services to the VO; and (3) Coordination of NRAO data management and science data post‐processing development with the standards and technology being developed by the VO community.

Development of the U.S. NVO has been underway for three years. A first version of the VO infrastructure, including a global resource registry and data access services, is in place. A first round of NVO applications was released to the user community at the American Astronomical Society (AAS) meeting in January 2005. The project is now in transition from a period of initial development to an operational mode. Development of the infrastructure will continue, e.g., adding support for authentication, asynchronous services, an advanced query language, large scale correlations, distributed work‐flows, and more sophisticated data models and data characterization standards.

In the data access area (which is led by NRAO), initial development has emphasized data access protocols for the major types of astronomical data, including catalogs, images, spectra, time series, etc. With completion of the initial set of data access protocols expected by fall 2005, the focus of development is starting to shift to integration of astronomical data analysis software with VO. A high‐level architecture for a component framework has been developed which could be used for desktop data processing and analysis, for pipeline processing, and to construct VO data access services (the latter compute on‐demand data products and hence are similar in many respects to conventional pipelines). This architecture is not specific to radio data but could eventually result in a new, scalable framework for radio data packages such as AIPS and AIPS++, with built‐in integration with VO for distributed computation and distributed access to data. This effort is being coordinated with NVO and IVOA and with OPTICON in Europe. Prototyping is already underway at various sites including within

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NRAO, at ESO, in the U.K., and at Space Telescope Science Institute (STScI) and National Optical Astronomy Observatory (NOAO).

Within the NRAO, an effort was started in January 2005 to develop a more comprehensive NRAO VO plan. The goal of this is to provide radio data and services to the VO. In particular we need to work toward the goal of providing reference images and spectra for observations with NRAO telescopes. Publication of such data to the VO will include standard IVOA SIA and SSA data services for access image and spectral data, and SkyNode interfaces for access to catalog data (some cone search services are already available). We also plan to provide a SIA service for VO access to visibility data.

In support of this effort, a study has evaluated approaches for processing archival VLA data to produce reference images which can be published to the VO. A plan for a VLA archive imaging pilot project was prepared in December 2004 which would produce images for continuum data for the VLA B configuration at 5 and 8.4 GHz, initially using data from a single semester (about 1,500 sources, resulting in three images per source). A prototype VLA imaging pipeline, based on the work done earlier for the VLBA, has already been implemented. In addition to pipeline processing to produce reference images, we also plan to support and encourage publication of science‐grade images prepared by observers. This will include support for global dataset identifiers to relate (via the ADS) images referenced in published papers back to images in the NRAO archive.

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Overview

The National Radio Astronomy Observatory (NRAO) education and public outreach (EPO) program provides leadership for the development of a scientifically and technically literate society; communicates extensively with the national and international astronomical community via print and electronic media; functions as an exceptional resource for K – 16 science education; communicates the Observatory’s mission and science to the media, science museums and planetariums; creates high‐quality publications; operates science centers that bring astronomy to the public in West Virginia and New Mexico; and increases national and international awareness of the Observatory and its programs.

The NRAO EPO staff coordinates and promotes astronomical education and public outreach activities Observatory‐wide. Each EPO program incorporates the most recent scientific results from the Green Bank Telescope (GBT), the Very Large Array (VLA), and the Very Long Baseline Array (VLBA), and discusses the scientific promise of the Expanded Very Large Array (EVLA) and the Atacama Large Millimeter Array (ALMA). NRAO EPO programs also describe how radio astronomy complements and connects to astronomical research at optical, infrared, ultraviolet, X‐ray, and other non‐radio wavelengths.

The NRAO EPO staff includes one full‐time employees and one part‐time employee in Virginia; five full‐time and seven seasonal employees in West Virginia; and two full‐time and two part‐ time employees in New Mexico. A member of the Charlottesville scientific staff, Juan Uson, functions in the role of EPO Scientist. This Observatory service position was created in FY 2005 to assist and provide scientific input to the EPO Division Head. The EPO Scientist also leads and manages the Legacy Imagery Project.

An EPO Advisory Committee has also been formed. Its primary function is to assist the Division Head and the Public Information Officers with the timely identification of news‐ worthy research conducted at the NRAO. The following scientific staff members currently serve on this committee: Tim Bastian (CV), Chris Carilli (SOC), Dale Frail (SOC), Harvey Liszt (CV), and Juan Uson (Chair).

FY 2005 EPO Highlights

In FY 2005, the NRAO EPO team undertook several new initiatives and enhanced a wide range of proven education and outreach programs.

A program for radio astronomy outreach to science museums and planetariums was inaugurated in FY 2005 via collaboration with the Space Telescope Science Institute Office of Public Outreach and the multi‐media program ViewSpace. NRAO EPO delivered a ViewSpace

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program module in June 2005 that enabled the distribution of NRAO science press releases to more than 70 museums and planetariums.

The Legacy Imagery Project was another FY 2005 new start. This project seeks to improve the Observatory’s capability to process radio‐wavelength astronomical data into compelling visual imagery and generate high‐quality image products. This program is led and managed by Juan Uson, who has explored radio data visualization techniques and has produced impressive radio – optical composite images. To involve the astronomical user community, and foster the widest possible dissemination of new results and images, EPO announced the first NRAO / AUI Image Contest at the summer 2005 AAS meeting in Minneapolis.

The Observatory’s Public Information Officers (PIOs) collaborated with the astronomical community in FY 2005 to produce sixteen press releases for world‐wide distribution based on results from the GBT, VLA, and VLBA. The exciting science described in these press releases included GBT’s amazing discovery of more than two dozen pulsars in the globular cluster Terzan 5. Six additional press releases announced special awards or events, e.g., Riccardo Giacconi being awarded the National Medal of Science. In October 2004, the NRAO hosted a workshop for PIOs that was sponsored by the National Science Foundation (NSF). Representatives from numerous research institutions attended.

To maintain close ties with the astronomical community, the NRAO exhibits at American Astronomical Society (AAS) meetings, describing user services, attracting new users, communicating Observatory programs and plans to the community, and supporting the AAS press room. In FY 2005, EPO staff represented the Observatory at the January and June AAS meetings in San Diego and Minneapolis. Significant improvements were made to the NRAO exhibits and the quality of the materials distributed. In September 2005, three display papers and one workshop describing NRAO EPO programs were presented at the Astronomical Society of the Pacific conference, Building Community: the Emerging EPO Profession, in Tucson. NRAO EPO also participated in the June 2005 IAU Working Group XII meeting Communicating Astronomy with the Public, in Germany. The NRAO hosted the April 2005 Southwest Consortium of Observatories for Public Education meeting at the VLA and provided a key presentation for the September 2005 STARTEC meeting.

In summer 2005, the Observatory offered a varied selection of education programs in West Virginia and New Mexico. A major new program, the 2005 West Virginia Governor’s School for Mathematics and Science (GSMS), was held at Green Bank, July 31 – August 13, in collaboration with the National Youth Science Foundation. Funded by the West Virginia Experimental Program to Stimulate Competitive Research, this program offered a unique educational opportunity for 60 gifted eighth grade students.

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Three teachers participated in the 2005 NRAO Research Experiences for Teachers (RET) program. Kurt Voss (Zuni, NM) worked with Mark Claussen, collaborating on a study of low‐ mass star formation. Vincent Pereira (Englewood, NJ) and Eric Kearsley (Silver Springs, MD) joined the 2005 RET program at Green Bank. Mr. Pereira’s research advisor was Brian Mason, and their research project developed imaging algorithms for a new high‐frequency GBT receiver. Karen O’Neil was Mr. Kearsley’s research advisor on a project to measure dust in low surface brightness galaxies.

A successful Chautauqua program took place at the Green Bank Science Center May 23 – 25, 2005. This three‐day summer residential education program serves undergraduate science faculty and has been a key element of the NRAO Education program for eighteen years, during which time more than 580 faculty have been trained.

The NRAO, White Sands Missile Range, and the New Mexico Institute of Mining and Technology collaborated in FY 2005 on a series of events that celebrated the 100th anniversary of Albert Einsteinʹs annus mirabilis. The VLA (celebrating its first twenty five years of science operations) and the Trinity Site (celebrating its 60th anniversary) were open for joint public tours, and an evening lecture by NRAO Assistant Director Jim Ulvestad described the history of the VLA.

Funding for GEAR UP (Gaining Early Awareness and Readiness for Undergraduate Programs) Camp was renewed for 2005 by the U.S. Department of Education, and numerous ninth and eleventh grade students benefited from an excellent three‐day residential program at Green Bank.

The Society for Amateur Radio Astronomers (SARA) held their 2005 meeting at Green Bank, June 19 – 21, and enjoyed numerous programs at the Science Center. The Central Appalachian Astronomy Club again held their large annual star party, Star Quest, at Green Bank in summer 2005, drawing 150 attendees. In New Mexico, the 11th annual Enchanted Skies Star Party was supported by EPO in October 2004.

The Quiet Skies Detector Teacher Workshop, funded by a NASA IDEAS grant, was held at Green Bank June 28 – 30, 2005.

Students from the Women in Science and Engineering (WISE) program at the University of New Mexico visited the Array Operations Center in late April shadowing NRAO employees to better understand the daily tasks of scientists and engineers. The students represented many majors. NRAO scientists demonstrated imaging software and explained their current research. Engineering students were treated to overviews of activity in the electronics labs.

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Visitation during FY 2005 was healthy at the Observatory’s Visitor Centers in New Mexico and West Virginia, and was particularly strong in Green Bank this past summer. A new exhibit was installed in April 2005 at the VLA Visitor Center that explains the major hardware and software modifications that are converting the VLA into the Expanded Very Large Array. The University of New Mexico ‐ School of Architecture produced draft architectural renderings in FY 2005 for a potential new VLA Visitor Center. The VLA Visitor Center Committee defined objectives and a draft business plan to accompany this architectural vision.

In FY 2005, NRAO EPO and scientific staff volunteered a wide range of service to their communities by supporting K ‐ 12 science activities in Green Bank, Socorro, and Charlottesville, providing speakers, judges, coaches, volunteers, prizes, and special tours. NRAO staff also visited schools to lead science enrichment activities for all grades and gave invited talks to civic groups. A joint NRAO, University of Virginia, and Charlottesville Astronomical Society public observing session was held at a dark site for the November 2004 total lunar eclipse; and a joint NRAO and Greenbelt Astronomy Club observing session was also held for the same eclipse.

FY 2006 EPO Program

World Wide Web

The World Wide Web is arguably the Observatory’s most important outreach and communication channel. In FY 2006, the NRAO Tiger Team, which was initially formed in August 2005, will determine the requirements for and manage the implementation of improvements to the Observatory’s website, http://www.nrao.edu. These improvements are intended to primarily address structure, content, and content management.

This Tiger Team includes representatives from the Director’s Office, Computing Information Systems (CIS), Charlottesville Computing, the Program Management Office, the scientific staff, and EPO. The Tiger Team is led from Charlottesville by the EPO Division Head and will include additional team members from Socorro and Green Bank. A significant fraction of the website renovation work will be performed by contractors with proven expertise in the design and implementation of websites of similar purpose, content, and scope.

The Tiger Team is addressing the renovation of the Observatory’s entire web site, including those portions that serve the astronomical user community, EPO constituents (the general public, teachers and students, the media, EPO professionals), and the NRAO staff.

The Tiger Team is also designing appropriate means to sample and understand the user’s needs and web site usage, involving astronomers from the NRAO Users Committee. A plan for the

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effective long‐term operation and maintenance of a national observatory’s website will also be designed by the Tiger Team and will be implemented at the earliest possible time, resources permitting.

Publications

The design, writing, and publication of an Observatory‐wide brochure will be a high FY 2006 priority within EPO. This brochure will concisely describe the mission, science, facilities, and capabilities of the entire NRAO in a single, professionally‐designed package. This brochure will be updated annually.

EPO will continue to design, edit, and publish the quarterly NRAO Newsletter. The newsletter’s distribution increased in FY 2005 by 16% to nearly 1,800 persons. Additional newsletter distribution increases are anticipated in FY 2006 and beyond as the Observatory extends it outreach to include a larger number of astronomers from around the world whose research is conducted primarily or entirely at non‐radio wavelengths.

Astronomical Community

NRAO EPO will actively participate in two meetings of the U.S. astronomical community in FY 2006. At each of these conferences, EPO will participate as exhibitors, press‐room and special event coordinators, representing the NRAO, bringing an improved understanding of the Observatory’s mission, science, services, and facilities to graduate and undergraduate students, astronomy and physics faculty, post‐doctoral fellows, and research staff.

EPO personnel will attend the winter (January 8‐12, 2006, Washington D.C.) and summer (June 4‐8, 2006 Calgary, Canada) meetings of the American Astronomical Society (AAS). Early in the fiscal year, EPO will re‐design the Observatory’s exhibits, updating their content, structure, and design. At the winter AAS meeting, in addition to their roles as exhibitors and press contacts, EPO will lead the planning and coordination of the EVLA and ALMA Town Meetings, special events that will communicate the progress and scientific promise of these important construction projects to the astronomical community. EPO staff will also plan and execute a press reception and press conference at the Washington D.C. AAS meeting on Monday, January 9, 2006.

EPO personnel are also involved in the international education and outreach activities of IAU Commission 46 (Astronomy Education and Development), the IAU Division XII Working Group (Communicating Astronomy with the Public), and the Astronomical Society of the Pacific.

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Legacy Imagery Project

Inaugurated in FY 2005, the Legacy Imagery Project is developing the Observatory’s capability to process astronomical data acquired at radio wavelengths into compelling visual images, and to use these images in conveying the NRAO mission and science to its constituencies. Images generated by each of the Observatory’s existing (GBT, VLA, VLBA) and future (EVLA, ALMA) research facilities will typically be combined with images from other wavelength regimes and observatories, creating multi‐wavelength composite images that offer unique, synergistic views of our Universe.

The annual NRAO/AUI Image Contest is a key component of this project. This image contest engages the astronomical community in the Observatory’s efforts to increase the number of high‐quality and EPO‐effective radio astronomy images. All contest images will be made widely available via the Observatory’s on‐line Image Gallery, which will grow year‐by‐year and become increasingly valuable as a resource for teachers, students, scientists, the media, and other EPO programs. These images will also be distributed via well‐designed EPO products including a large‐format color poster series.

Figure 10.2. Legacy Imagery Project optical‐radio composite image of the Whirlpool Galaxy, Messier 51. Neutral hydrogen 21 cm VLA radio data courtesy A.H. Rots (NRAO), A. Bosma (O. Marseille), J.M.Van der Hulst (Groningen), E. Athanassoula (O. Marseille), and P.C. Crane (NRAO). Optical data courtesy STScI/POSS‐II.

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Science Museum Outreach

The Observatory’s Science Museum Outreach initiative brings radio‐wavelength scientific research and the NRAO into more than seventy major science museums and planetariums in North America. The Observatory’s goals for this program are being accomplished through its participation in ViewSpace, a free multi‐media electronic exhibit developed and managed by the Space Telescope Science Institute Office of Public Outreach (STScI OPO). In addition to their distribution through existing print and electronic press release channels, all NRAO scientific research press releases accompanied by high‐quality imagery and/or graphics are now also distributed via the ViewSpace network.

Figure 10.3. Lead, content, and credit templates for the NRAO ViewSpace program module that convey GBT scientific press releases to more than 70 science museums and planetariums.

News and Media

Ensuring that scientific research conducted at the NRAO receives excellent international news and media coverage is another important long‐term EPO responsibility. EPO seek the widest possible dissemination of NRAO research results through the mass electronic and print media. This effort is time‐intensive, requiring continual cultivation of reporters, editors, and other contacts in the media, press rooms, and at press conferences.

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The NRAO public information officer (PIO) writes and issues twenty to thirty press releases per year, working closely with scientists who have used NRAO telescopes, with Observatory management, and with the National Science Foundation Office of Legislative and Public Affairs. Joint press releases are often generated in collaboration with PIOs at other universities and research institutions. NRAO press releases are electronically distributed to more than 1,500 science journalists world‐wide and via ViewSpace. This distribution will increase, especially via web‐based news organizations. All NRAO press releases are available at the Observatory’s website. Web‐based news organizations, such as Space.com, often link directly to NRAO press releases and images.

Though the EPO public information officer is well‐connected to the scientific community, it is difficult to track the best research being performed in every field of astronomy across the Observatory. Thus, an EPO Advisory Committee has been formed to assist with the timely identification of scientific research conducted at the NRAO that might be particularly newsworthy.

In FY 2006, EPO will implement metrics designed to measure the effectiveness and media penetration (quantity and quality) of the Observatory’s press releases.

Public Science Centers

The Green Bank Science Center in West Virginia and the VLA Visitor Center in New Mexico are popular and offer numerous educational programs designed for the general public. The visual impact of the GBT and the VLA and the intriguing, well‐publicized accomplishments of modern astronomy are major draws for the general public. The self‐directed and guided tours enabled by the on‐site EPO staff in West Virginia and New Mexico made visiting these NRAO facilities an enjoyable and enriching experience for more than 63,000 people in 2004, and visitation is expected to show continued increases.

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Figure 10.4. Opened in May 2003, the NRAO Green Bank Science Center in West Virginia attracts more than 40,000 visitors per year.

The Observatory recently commissioned a study by the University of New Mexico School of Architecture & Planning for a larger VLA Visitor Center that would enable education and tour programs comparable to those offered at the Green Bank Science Center. The NRAO is considering several methods to finance the construction of a new VLA Visitors Center, with a goal of construction beginning in FY 2011.

Figure 10.5. A new, expanded NRAO VLA Visitor Center in New Mexico would offer educational programs, exhibits, and tours comparable to those available at the Green Bank Science Center.

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This architectural study, the Green Bank Science Center construction, and the VLA Visitor Center 2003 expansion, were all funded outside the Observatory’s NSF‐AST budget. Similarly, the NRAO recognizes that it can only build a new VLA Visitors Center if funding can be identified from sources outside the NSF‐AST budget.

Education

The Observatory’s education programs in New Mexico and West Virginia are healthy and growing. The NRAO Education Specialists at these sites host multiple educational opportunities for K–16 teachers and students each year.

The Research Experiences for Teachers (RET) program, funded by the National Science Foundation (NSF), is a mainstay of the NRAO education program. The NSF‐RET program annually funds three or four secondary‐school teachers for an eight‐week summer program in West Virginia, New Mexico, or Virginia. Since this program is often constrained by competition with the NSF Research Experiences for Undergraduates (NSF‐REU) program for mentors, the NRAO has recently requested approval from the NSF to schedule some RET participants as visitors during the fall or spring school semester rather the summer.

The Master of Science Teaching Class in observational radio astronomy was planned and offered for the first time by the NRAO at the New Mexico Institute of Mining and Technology in summer 2004. The EPO long‐term plan is to offer this education program every other summer, i.e., in 2006, 2008, and 2010.

The Governor’s School for Mathematics and Science (GSMS), a collaboration with the National Youth Science Foundation, was held in Green Bank for the first time in 2005, offering a unique two week science‐education opportunity to the sixty gifted eighth‐grade students who were selected from more than 300 applicants. In collaboration with the National Youth Science Foundation, the NRAO has been funded for a second year of the GSMS in Green Bank in summer 2006.

The NSF‐funded, long‐term RARECATS program will continue through at least FY 2006 at Green Bank, giving K‐12 teachers an outstanding hands‐on research experience. Teachers graduating from this program often return to the NRAO with their students to use the 40‐foot Green Bank telescope. RARECATS and its predecessor workshops have been extraordinarily effective, having reached more than 5,000 teachers.

EPO’s Quiet Skies program is funded by a NASA IDEAS grant. Initiated in FY 2004, the Quiet Skies project has already designed, produced, and tested an inexpensive prototype radio frequency interference (RFI) detector which operates at 800, 1420, and 1665 MHz. The education program plans for summer 2006 includes hosting twenty teachers for a weekend

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workshop to learn how to integrate radio astronomy and Radio Frequency Interference (RFI) into their high school science curricula. Schools and students from across the United States will borrow these detectors and measure RFI in their communities, reporting their data and results to a database maintained by the NRAO.

The Observatory will initiate an NRAO Navigator Program in FY 2006. Modeled on the successful NASA – JPL Solar System Ambassadors Program, the NRAO Navigator Program will train motivated volunteers from across the United States to communicate the excitement of the NRAO mission and science to people in their local communities. Though resources constrain the NRAO program to a necessarily modest beginning, the NRAO EPO program will seek to leverage its initial eight Society of Amateur Radio Astronomers volunteers into an increasingly large and effective team. Begun in 1998 after the Galileo mission, the NASA – JPL program has grown to include 459 Ambassadors in fifty states and Puerto Rico.

In collaboration with a West Virginia radio station, EPO will initiate a pilot program in FY 2006 to script and produce two‐minute radio programs about astronomy. Possible program topics include noted astronomers (Jocelyn Bell, Grote Reber, Edwin Hubble), astronomical phenomena (pulsars, black holes, planet formation, meteor showers), and new science initiatives (Atacama Large Millimeter Array). This radio series will be developed for potential distribution through National Public Radio and other high‐profile venues.

Chautauqua Short Courses have been a fixture at the NRAO for eighteen years and have served more than 580 undergraduate science faculty who visited the Observatory to update their science course content and pedagogy. EPO plans to continue these annual short courses in New Mexico and West Virginia.

EPO will also continue its long‐term outreach collaborations with the amateur optical and radio astronomy communities by continuing its annual programmatic and logistical support for the StarQuest (West Virginia) and Enchanted Skies (New Mexico) star parties, and through its hsting of the annual Society for Amateur Radio Astronomers meeting at Green Bank.

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Overview

The responsibility and authority to manage the Observatory is delegated by Associated Universities, Inc., (AUI) to the NRAO Director, Dr. K. Y. Lo, who reports to the President of AUI. Each of the NRAO functional units within the Observatory is led by a senior manager, all of whom work under the supervision of the Director or the Deputy Director, Dr. P.R. Jewell.

The NRAO is organized as “one Observatory,” i.e., as a single Observatory with a central management and centralized functional authority for those activities that contribute to the effectiveness of all Observatory endeavors. Despite the geographic separation of the operating sites, priorities for the NRAO programs are established via various discussions across the entire Observatory.

Figure 11.1 shows the top‐level NRAO organization chart recently adopted by the Observatory:

• Four operational units report to the Director: NRAO Operations, Science and Academic Affairs, the ALMA Project, and Administration:

• The New Initiatives Office, under the direction of K. I. Kellermann, the Chilean Affairs Office, under the direction of E. Hardy, and the Program Management Office (PMO), which includes the Management Information Services Division, led by D. H. Hubbard, are all staff units reporting to the Director.

• NRAO Operations are led by the Deputy Director, P. R. Jewell: New Mexico Operations (J. S. Ulvestad), Green Bank Operations (R. M. Prestage, interim), the Central Development Laboratory (J. C. Webber), Education and Public Outreach (M. T. Adams), Software Development (vacant), and Computing and Information Services (G. C. Hunt). These six operational units comprise a large fraction of the personnel and resources of the Observatory and include all of the Observatory’s existing astronomical research facilities: the Very Large Array, the Very Long Baseline Array, and the Green Bank Telescope.

• The Observatory Administration group is headed by the Associate Director for Administration, George Clark. The Administration group is responsible for business operations at the Observatory, including Business Services (e.g., budget planning and monitoring, contracts, and procurement) Fiscal, Human Resources, and the Environment, Safety, and Security group.

• The Division of Science and Academic Affairs (DSAA) is led by W. M. Goss and serves as the base organizational unit for Observatory research and student staff.

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• The ALMA Project organization is led by A.P.G. Russell. The ALMA Project is comprised of two major organizational units: the North American ALMA Construction Project, also led by Russell, and the North American ALMA Science Center, initiated in FY 2005 and for which P.A. Vanden Bout is interim Director.

The Director and Observatory management regularly seek advice and guidance from the astronomical community through an active and involved set of external advisory committees that includes, the Visiting Committee (appointed by and reporting to AUI), the Users Committee, the EVLA Advisory Committee, the Program Advisory Committee, the ALMA North American Scientific Advisory Committee (ANASAC), and ad hoc committees that advise the Director on instrumentation and policies. Oral and written inputs received from these committees are accorded high priority by the Director and the Observatory. These committees, and others, provide input that is vital to the generation of the NRAO strategy and priorities, both within individual sites (i.e., VLA/VLBA, GBT) and across the Observatory. The Observatory also seeks frequent communication and contact with the astronomical community‐ at‐large through the participation of NRAO staff at conferences such as the semi‐annual American Astronomical Society meetings. Through attendance at such meetings, the NRAO actively supports its users, promotes radio astronomy’s immense discovery space, and works toward increasing the number of future radio astronomers and Observatory users.

Excellent communication within the Observatory is vital to its effective management. The Director has instituted several initiatives that will continue into FY 2006 and provide for improved communication throughout the Observatory such as a series of regularly scheduled and effectively organized senior management meetings created to form the foundation of improved communication within the Observatory:

• The Director meets with the Executive Management Team (Deputy Director, Associate Director for Administration, Head of the Division of Science and Academic Affairs, ALMA NA Project Manager, and the Head of the Program Management Office) monthly for a high‐level review and discussion of Observatory programs, priorities, issues, policies, personnel, and future directions. These meetings are normally an hour in length, with participants joining in via teleconference when away on travel.

• A larger team of senior managers, the Executive AD group – meets via videoconference once per month. This group includes the Director’s Executive Management Team as well as the Assistant Directors and major project managers representing all Observatory facilities, which is a forum that is best suited to debating and setting NRAO short‐ and long‐term strategic plans and priorities. The Executive AD group is further responsible for the complex decision‐making that translates NRAO strategic plans and vision into well‐managed, scientifically productive astronomical research facilities which most effictively serve the professional astronomical community at large. This translation

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demands that the Executive AD group decide Observatory‐wide scientific, technical, and managerial priorities only after carefully considering their implications for the entire domain of NRAO programs, projects, operations and users. Final decisions and priorities are the prerogative of the Director.

• A new NRAO Operations meeting was initiated in September 2005. Chaired by the Deputy Director, the NRAO Operations meeting attendees include the heads and deputies of the Observatory operational units in New Mexico, West Virginia, and Virginia representing the Green Bank Telescope, the Very Large Array, the Very Long Baseline Array, the Central Development Laboratory, Education & Public Outreach, Observatory Software, and Computing & Information Services. This forum convenes for an hour on the second Thursday of each month to communicate, discuss, and resolve operations issues within an Observatory‐wide perspective.

In addition to these meetings, Observatory communication is encouraged through the reporting of monthly activity highlights which are generated by senior management and include recent news items, technical, scientific, and managerial issues, and assesses the status of critical programmatic and policy milestones. These reports are distilled by the EPO Division Head into monthly informational emails that are distributed to all NRAO employees, AUI executives, external NRAO committee members, and key NSF/AST program managers.

Management of NRAO activities – operations and construction – is conducted via the comprehensive Observatory Work Breakdown Structure (WBS), a critical management tool. The WBS is a hierarchical decomposition of all NRAO tasks into their component parts. The WBS presents task components in successive levels of detail that combine to accurately describe each activity’s entire scope. By organizing the Observatory accounting structure and personnel assignment on the defined WBS elements, cost and effort is properly and routinely reported.

All Observatory activities, including the ALMA and EVLA construction projects, are incorporated into the WBS. Basing Observatory activities on the WBS provides the institutional framework necessary for the Observatory to take on new tasks or modify existing tasks in a straightforward manner while maintaining full accountability.

Below you will find full descriptions of the Administration, Scientific and Academic Affairs, and Program Management Office Divisions, as overviews of recent and upcoming activities within the Computing and Information Infrastructures within the Observatory.

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Figure 11.1. NRAO Top –Level Organization Chart

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Administration Business Services

The Administration, Grants and Agreements Management, Business Analysis, and Facilities groups of Business Services provide the business support for Charlottesville operations and Observatory‐wide requirements including non‐programmatic grants, non‐health related insurance, and lease management.

During FY 2006, Business Services will expand its reach and responsiveness through the use of integrated systems that are built upon a common database and standardized work flow processes. By increasing the reliance on electronic document processing, Business Services will be able to consistently provide the reporting of budget performance, identify areas requiring special attention, and redeploy administrative employees as needed to complete new tasks without adding to staff. Among the areas of expanded efforts will be to:

• Provide direct support to budget holders to develop, track, and measure performance against budgets. • Provide detailed analysis of current budgets and assess future requirements. • Expand analysis and support of non‐programmatic funded grants. • Expand support of grants administration and their associated sub‐awards including host institution coordination for Jansky Fellows and observing grants for Hubble, Chandra, and Spitzer telescopes.

Business Services also includes the Procurement and Contracts group. This group continues to bring about efficiencies and cost saving initiatives through electronic procurement and e‐ commerce. Last year the Observatory’s Program Management Office (see PMO section below) started the first module of the WBBS initiative, Procure 2 Pay (P2P). This initiative has been very successful in improving the communication, status, and processing of purchase requisition. P2P has allowed the Observatory to track purchase requisitions in real‐time, reduce turn around time for a requisition from days to minutes, and streamline the approval process. The result has been a much more responsive Procurement organization; tracking and reporting capabilities have been placed in the hands of users and managers. The implementation of the P2P opens the way for other e‐commerce initiatives such as Procurement Cards (P‐Cards), Travel and Entertainment cards, and e‐Procurement of commodities through national contracts. Once these initiatives are implemented, the cost of processing a purchase order can be reduced by up to fifty percent.

This past year the Procurement and Contracts Division established an import/export department to provide import/export services, guidance, and training to all NRAO projects. Key personnel were added to this department and trained in import/export procedures. In

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addition, import/export awareness training was conducted at all NRAO sites. Currently, the import/export office is effectively processing, tracking, and reporting requests from Observatory projects. Procurement and Contracts is also reinforcing awareness about import/export procedures and forms through online documentation.

FY2006 will continue to bring new initiatives for the Procurement and Contracts Division, which will further enhance customer service. These initiatives include a transformation from a transactional organization to a customer focus‐driven organization. This will position the Procurement and Contracts Division as a strategic partner within the Observatory to accomplish Observatory goals.

Fiscal

As part of the Web Based Business Services (WBBS) initiative, three Fiscal functions are scheduled to be transitioned to electronic processing during FY 2006: General Ledger and Job Cost, Payroll, and Time and Attendance (Electronic Timecard Systems – ETS).

The implementation of the WBBS system will shift many tasks from labor‐intensive data generation and entry processes into an automated data collection, review, and management reporting environment.

Environment, Safety, and Security

NRAO is recognized as a global leader in radio astronomy, maximizing value for the scientific community by integrating environmental, safety, and security considerations into our decision‐ making. Our vision is to establish and maintain a healthy and safe work environment at NRAO facilities. Our approach in achieving this vision will be to involve NRAO staff, visitors, and the scientific community with initiatives designed to develop staff members who can identify and proactively mitigate potentially hazardous conditions.

The NRAO will continue to be a leading example in environmental protection, and to reduce the number and severity of accidents at our facilities. The Observatory will also continue to identify methods to improve the security of our facilities via non‐invasive methods. With the support of local and senior Observatory management, the ES&S Division will continue to provide guidance for protection of the environment, and support a safe and secure workplace for our staff and visitors.

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Environmental Protection

The NRAO is committed to being a positive and creative force in the protection and enhancement of the environment when engaged in research and administrative operations. Recognizing that some activities may have impacts to the environment, all employees have the responsibility to act consistently with environmental principles and objectives.

In the coming year, the NRAO Environment, Safety and Security (ES&S) team will initiate and support an external environmental audit of our major facilities. This will include a representative VLBA site to identify waste stream materials to ensure appropriate waste processing. Additionally, the audit will identify areas of non‐compliance and provide recommendations to further the objectives of the NRAO with respect to maintaining a healthy relationship with the environment.

The ES&S team will continue to coordinate and ensure proper disposal of hazardous wastes generated in the NRAO facilities. This year, ES&S will further formalize an Asbestos Management Program in all facilities where asbestos has been identified. This program will include the training of specific employees in the management and disposal procedures of asbestos materials and will include oversight of all asbestos removal projects to ensure the health and safety of employees and visitors.

Safety in the Workplace

The NRAO Occupational Safety Program is designed to:

• Establish challenging targets at every level to reduce work‐related injury and health damage. • Ensure an effective safety management system, led by senior and line managers, supported by safety representatives. • Emphasize safe design and communicate lessons learned from accidents and incidents. • Deliver health and safety services, including training, capable of meeting health needs at work. • Ensure that the actions of contractors, suppliers, customers, and partners are consistent with our standards. • Meet or exceed regulatory requirements and apply industry standards, codes, and best practices in the absence of regulations. • Proactively and constructively participate in the formulation of safety policy and procedures.

In the coming year, ES&S will strive to meet the above goals by providing, on a monthly basis, safety education and awareness training to appropriate employees. NRAO will limit

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occupational injures and illnesses by emphasizing safety education and safe work practices for all employees.

Additionally, ES&S will begin a proactive program of inspection and training for the VLBA facilities. ES&S will develop VLBA specific safety training sessions for operators. As part of the VLBA effort, we have established a goal of inspecting five VLBA stations during FY 2006.

ES&S will also play an essential role in the development of the ALMA safety program. ES&S has developed an aggressive schedule for ALMA safety policy and program development focused on the consolidation of international safety requirements for implementation at the ALMA site. Significant resources are planned to ensure completion of this goal within the next fiscal year.

Secure Facilities

It is essential to protect staff and visitors through a continuous, cost effective, and sustainable state of readiness that is resistant to threats and prepared for natural disasters. The NRAO is committed to protect our staff and visitors as well as preserve personal and government property from damage or loss. The responsibility for developing and maintaining a safe, secure, and welcoming environment belongs to all employees.

In the coming year, ES&S will draft an NRAO Security Philosophy to provide guidance and priority in the procurement and implementation of security measures at the NRAO facilities. This philosophy will address a policy on the use and distribution of access cards for secure access control. ES&S will also continue the development of remote monitoring of common areas at each of our facilities.

Human Resources

The Human Resources (HR) Division, in partnership with NRAO management, ensures a qualified, diverse, and highly motivated workforce focused on achieving the strategic goals of the Observatory through the development of cost‐effective and results‐oriented human resource programs, policies, and practices. The goals for the Division are:

• Create an environment that permits the Observatory to attract and retain a highly skilled, productive, diverse, and efficient workforce. • Develop, implement, and administer policies and procedures that ensure fair and lawful treatment of employees. • Provide management with quality and timely services, information, and advice to support planning and decision making.

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• Develop, implement, and administer HR programs that enhance retention and maximize productivity and effectiveness of employees.

To meet the increasing demands on the Division due to the inclusion of the ALMA Observatory in Chile and the EVLA construction project, the division will focus over the next several years on defining methods to streamline the work of a small Human Resources staff.

Human Resources Information Systems

The Human Resources Information System (HRIS) provides the tools to meet the Observatory’s informational needs for Human Resources. Current demands for vital personnel data are required from every conceivable customer. These demands range from management reports of personnel count and labor allocation, to requests from funding sources, to compliance reporting, and benefit support.

The Human Resources Division staff will continue to be an important partner in a new fully integrated web‐based system with the payroll, general ledger, procurement, and a new production time‐tracking system. By late summer FY 2005, the Human Resources portion of the system will have run in parallel mode with the legacy system. The Supervisor and Employee Self‐Service modules are scheduled for roll‐out the first and second quarters of FY 2006. These enhancements will provide greater access and ownership of important work and employment information to all Observatory staff and enhance their performance potential.

Recruitment

Significant time and energy was placed on the recruitment of technical professionals and managers for the EVLA and the construction phase of the NA ALMA project in FY 2005. The projects have ushered in a new Project Management model for the Observatory. The creation and recruitment of a Project Controller and Project Scheduling Personnel added a new discipline to the Jobs and Compensation structure.

The HR Division focuses on the technical competencies required to fill each job vacancy. Once established, the job opening is placed in one or more public venues. These consist of scientific and technical journals and related employment web pages, nationally available web‐based employment services, and the Observatory’s own employment web page. Utilization of temporary employee service providers has increased and this trend is expected to continue in FY 2006 with the dual benefit of providing the much needed short‐term workforce through the final U.S.‐based phase of the EVLA and ALMA construction projects thereby reducing the need for downsizing as these projects are completed.

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Compensation and Benefits

The NRAO has made progress in approaching market competitiveness with the research community. However, the Market Assessment Update report prepared by Mercer Human Resource Consulting indicated the Observatory did lose ground in FY 2005 in relation to the marketplace. The concern going forward will be to have adequate funding to remain competitive looking given the expected flat FY 2006 and FY 2007 .

The benefits plans of the Observatory continue to be a strong retention tool in a time of tight budgets. In FY 2005 the Division rolled‐out a voluntary employee contribution life insurance plan for employees and dependents who desired to have life insurance they could carry with them at retirement or through a change of employer. This benefit provides an extra layer of personal comfort to replace employer‐provided term insurance that ends when employment ends. Federal legislation created Medicare D, the prescription drug option, for retirees. The Division has evaluated the pros and cons for the retirees and the Observatory and education materials have been developed to communicate the options to current and future retirees. As healthcare costs continue to escalate, the Observatory will be required to consider modifications to the plans.

Diversity

In FY 2006 the Human Resources Division intends to support and promote Observatory‐wide diversity initiatives. For example, the Observatory intends to attend and exhibit at the National Society of Black Physicists and the National Society of Black Engineers Conferences.

The Division took the lead in the formation of the Observatory’s Ad Hoc Committee on Diversity which will this year become a standing committee. Originally mandated to identify better methods of recruiting future scientists and managers, the Committee will focus its efforts on analyzing recruitment policy, formalizing selection policies and procedures, and training hiring authorities in the selection process. The committee will evaluate the Observatory HR‐ related policies and procedures to incorporate pertinent elements of the “Pasadena Recommendations” on gender equity as endorsed by the American Astronomical Society Council in January 2005.

This year, the Division will initiate discussions with one or more Historically Black Universities. If resources are available a Cooperative Education program could be instituted for undergraduate students with hopes to establish programs at the Masters level in engineering and computer science.

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Non‐Immigration Visas

As with most research institutes, the Observatory has been severely impacted by recent national and international security concerns. The process of filing and maintaining non‐immigration visas is no longer a small administrative task but has become a significant focus of time and effort within the HR Division. The Observatory continues to work with ever‐changing Federal requirements in the Exchange Visitor and Non‐immigrant work visa application and processing regulations.

In June 2005, the United States Citizenship and Immigration Services promulgated rules that prohibit foreign nationals on student non‐immigrant visas from receiving Exchange Visitor visa without leaving the U.S. for one year. While the Observatory is evaluating other options to recruit these most qualified future researchers, the impact to students and the Observatory will be palpable.

Training and Development

In FY 2005, the Division conducted the second phase of the Observatory‐wide Management Training Program with the focus on developing managerial and leadership skills. The training program, a collaboration of the Human Resources Division and the University of New Mexico’s Professional Development Center, provided a five‐day training experience for two dozen first line supervisors. In FY 2006, the program will continue for managers and supervisors who have yet to attend these training programs.

With the roll‐out of the Supervisor and Employee Self‐Service HRIS system the Division will work with the Program Management Office to develop and promote portions of the training for Observatory staff. This effort will include various training methods for all strata of employees from everyday computer users to those with limited or no current computer access at all. Training to remote site employees will also be required.

ALMA/Chilean HR Policy

The number of ALMA/NRAO employees stationed permanently in Chile is continuing to rise. As the project construction continues to ramp up and as the ALMA Observatory becomes more labor intensive, the need for a complete Chilean Human Resources structure is imperative. The focus for the Human Resources Division in FY 2006 will be to design policies and procedures that comply with the needs of each of the Executives and the Chilean labor system.

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Division of Science and Academic Affairs

The Division of Science and Academic Affairs (DSAA) was created in 2003 to address the interests and concerns of the scientific staff. The DSAA recently completed a new Scientific Staff Policy document which describes two parallel tracks for advancement leading to tenure or continuing appointments, Astronomer and Scientist. It specifies the research opportunities and Observatory responsibilities corresponding to all levels on both tracks. This Policy should improve morale and reduce stress among the junior staff members who are uncertain about the amount of time that can be devoted to their own research and the standards by which their performance is evaluated.

The Director has instituted a more regular schedule for meeting with the scientific staff as a group, and he will have more time for personal interaction with individual scientists since the complete NRAO management team is now in place.

Program Management Office Introduction

The Program Management Office (PMO) provides Observatory‐wide program management support to all aspects of Observatory projects including telescope construction, hardware and software development, and telescope operations. The PMO is responsible for providing program management support to ensure on‐time, on‐schedule delivery for each project in the Observatory, and applying mitigation strategies as necessary to maintain project critical paths.

In conjunction with NRAO senior management, the PMO has three broad‐based plans to define and execute:

• Modernize the NRAO business services and systems, • Integrate effective program management controls across all Observatory programs, and • Participate in the planning of new Observatory programs.

While not a traditional role of a program management office, the NRAO PMO is leading the modernization of Observatory business services and systems. The objectives of this effort are to improve the accuracy and timeliness of all business information, to provide the foundation for program management controls, and to reduce administrative effort of these business services. To successfully accomplish this effort will require the participation of key stakeholders across all divisions and programs of the NRAO.

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The integration and utilization of program management controls is the primary role and responsibility of the PMO. This effort will provide the mechanisms and metrics to perform assessments of all Observatory programs; the capability to monitor budget, cost, schedule, and risk of Observatory programs on a monthly cycle; and the early warning triggers to engage with NRAO project and program managers to launch mitigation strategies that maintain the critical path of these programs.

During FY 2004, these broad‐based plans were translated into four specific initiatives with specific, measurable objectives and deliverables to achieve stepwise maturity of Observatory business systems and program management functions. These initiatives are executed in parallel and include:

• Web Based Business Services • NRAO Program Management Control System • Program Standards and Processes • Program Management Assessments

The first initiative involves the modernization of the NRAO business systems referred to as Web Based Business Services (WBBS). This initiative requires a multi‐year implementation phase for the design and deployment of the business services as well as a major architecture upgrade to platforms that meet the performance requirements of the observatory. The implementation of these business services began in November 2004 with all high priority services scheduled for completion by the end of calendar year 2005. Implementation of the remaining business services will be completed in FY 2007.The remaining initiatives are related to traditional PMO operations and include the NRAO Project Management Control System (PMCS), Program Standards and Processes (PSP), and Program Management Assessments (PMA).

The following sections discuss FY 2005 accomplishments, detailed planning and implementation information for all PMO initiatives, and key objectives and targets to accomplish over the PMO 5‐Year Strategic Plan for FY 2006 through FY 2010.

FY 2005 Accomplishments

The major focus for FY 2005 was the implementation of the high priority Web Based Business Services; however progress and milestones were accomplished for all PMO Initiatives. Table 11.1 provides a summary of these achievements.

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Table 11.1 PMO Accomplishments for FY 2005 PMO Initiative FY 2005 Accomplishments WBBS: • Procurement Service operational Observatory‐ wide • Fiscal ‐ Accounts Receivable operational Observatory‐wide • Human Resources operational Observatory‐wide • Architecture Upgrade completed PMCS: • Planned and Initial Design PSP: • Observatory‐wide WBS normalized • WBS Change Control Process defined and in operation • NRAO Formal Inspection Process defined and in operation • Contract Deliverable Approval Process defined and in operation PMA: Program Management • PMO project assessments Assessments • ALMA Program Assessments • CIS Project Assessments New Program Development • NAASC programmatic support • FASR proposal support • GB 43m (MIT/LL) Antenna Proposal Review

For the WBBS initiative, the Procurement Service was the highest priority service driven by the extensive generation of requisitions anticipated by the Socorro Electronics Group and the ALMA program in FY 2005. The Focus Group for this service was the Socorro Electronics Group who began operation for this new service in March 2005. This service went operational Observatory‐wide in May 2005.

Operational data for this service include:

• To date, online requisitions have generated up to $50M in value; • 228 NRAO users were trained in seventeen Web‐based refresher training sessions available via the NRAO intranet; • As of August 2005, nearly 1,000 requisitions representing approximately 3,000 line items have been processed; • Requisitions have been exclusively paperless since July 15, 2005.

Other WBBS services completed in FY 2005 include Accounts Receivable, which went operational Observatory‐wide on July 18, 2005, and Human Resources, which is scheduled to be operational Observatory‐wide in November 2005. The WBBS architecture upgrade was

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completed in late August 2005. In addition to meeting NRAO performance requirements, this upgrade is a transition from proprietary hardware and databases to industry standard Intel/NT computing platforms with standard SQL servers and databases. The new architecture will lower long‐term Operations and Maintenance cost and give NRAO the ability to more easily move these systems to an Out‐Host provider in the future.

The other initiatives provide the foundation for normal PMO operations and include the PMCS, PSP, PMA, and new program development. In FY 2005, the PMCS was planned including the initial design. The PMCS is scheduled for final design and implementation in FY 2006, budget allowing.

The PSP initiative includes the PMO ownership and maintenance of the NRAO Work Breakdown Structure (WBS). The NRAO WBS was normalized in FY 2005 to achieve consistent project management reporting across the Observatory. A formal WBS Change Control Process was defined and put in practice in FY 2005. The PSP also includes the definition and training of NRAO personnel in proven project and program management processes and best practices. In FY 2005 an NRAO formal Inspection Process and NRAO formal Approval of Contract Deliverables Process were defined and put in practice during FY 2005.

Program Management Assessments began in earnest in FY 2005. The PMO has held bi‐weekly Program Reviews during the entire WBBS Implementation phase. This has helped the PMO to improve the PMA process and metrics that will migrate for assessments on other NRAO projects. Program reviews were also held for the ALMA program and for CIS projects. Program Management Assessments will continue with these PMA focus groups in FY 2006. After completion of the implementation of the WBBS high priority Business Services and the PMCS, Project Management Assessments will be routinely held Observatory‐wide.

PMO Detailed Plans and Status

The Program Management Office execution roadmap is shown in Figure 11.2. The controlling, key documents are the Program Management Plan, the Program Management Office Budget, and the Program Management Office Master schedule. For each initiative, the PMO has specified the critical components and deliverables.

A Program Management Office Initiatives Working Group, composed of over 50 key stakeholders across all divisions of the Observatory, has been established to ensure the success of the WBBS, PMCS, PSP, and PMA initiatives. This group will have active participation during the complete lifecycle of each initiative including: design, implementation, deployment, training, operations, and maintenance.

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As new systems and improved workflows are deployed, training becomes paramount to the organization’s effectiveness in executing these initiatives. A comprehensive approach to training is therefore a key objective of the Initiatives Working Group. Extensive training will be provided to the entire Observatory organization by the Program Management Office.

Program Office Program Program Office Budget Management Plan Master Schedule

Program Management Program Standards Program Management Web Based Control System & Processes Assessments Business Services (PMCS) (PSP) (PMA) (WBBS) Initiative Initiative Initiative Initiative

Standardized NRAO WBS PMCS System Performance OPERATIONAL Normalization PLANNED IN IMPLEMENTATION Reporting OBSERVATORY-Wide

NRAO Measured Level Published Of WBS Performance Property Reporting Payroll Procurement Management

WBS Change Control Process Fiscal Human Travel (GL, AP, Job Resources Formal Cost) Inspection Process Fiscal Team Formal (AR) LEGEND Calendaring Employee Self Acceptance Services Controlling Process Documents Initiative Processes for Measured Planned Level of Maturity

In Implementation

Operational

Figure 11.2. Program Management Office Execution Roadmap.

PMO Operations‐ Project and Program Management Initiatives

The fundamental role of the Program Management Office is to perform periodic Program Management Assessments across all Observatory Programs. The objective of these assessments is to evaluate cost, schedule, and critical path against the program’s planned budget, actual cost and schedule so that early detection of variances that exceed acceptable thresholds can minimize program impact by implementing timely mitigation strategies. A program’s ability to produce appropriate metrics for these assessments is dependent on the Observatory’s Program, Project and Portfolio management maturity.

Modernization of NRAO Business Services ‐ WBBS Initiative

The objective of Web Based Business Services is to host all NRAO business services and associated applications on a common architecture consisting of browser based clients accessing server applications and backend SQL server databases.

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The new architecture shall offer the following benefits to the NRAO:

• Consolidation of data • Optimize business services hardware and software • Eliminate need for home grown “specialized tools” • Reduction of human intervention (copying and moving data) • Eliminate multiple data entry • Automation of processes and reporting

Figure 11.3 shows the decomposition for the seven major business services of the Observatory.

Web Based Business Services

Property Human Employee Self Procurement Fiscal Payroll Management Travel Resources Services Business Business Business Business Service Business Business Service Service Service Service Service Service

Accounts Accounts General Ledget Job Cost Receivable Payable (GL) (AR) (AP)

Figure 11.3. WBBS System Decomposition for the 7 Major Business Service Areas.

Each service consists of one or more subsystems, features, and functions. For example, the Fiscal business service is composed of the following subsystems: General Ledger, Accounts Receivable, Accounts Payable, and Job Cost. Further analysis has identified that within the seven major business services areas there are fifty nine significant business functions that require upgrading.

After a diligent review of vendor products, PeopleSoft’s Enterprise One was selected as the core software platform to host WBBS services. Implementation of the Business Services on this platform began in Q1 of FY 2005 and consists of the seven service areas, with varying complexity, as shown in Figure 11.4.

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Implementation Complexity of Business Services

Travel Service Completed in FY2005

Payroll Service Completes Q1 FY2006

Completes in FY2007 Human Resources Service

Employee Self Services

Procurement

Fiscal Management

Property Management Service

0.00 0.20 0.40 0.60 0.80 1.00 1.20 Complexity (1=Highest)

Figure 11.4. Implementation Complexity and Completion Status of Business Services.

A rigorous, formal development lifecycle is used for implementation of each Business Service consisting of:

• “As Is” Requirement Specification, • “To Be” Requirements Specification, • Design, • Prototyping, • Implementation, • IV&V, Training, • Deployment, • Initial O&M, • with milestones for Operational Observatory‐Wide and Post Implementation Audit.

Progress for Business Service Implementation is tracked through formal Project Management Assessments at 2‐week intervals. Figure 11.5 illustrates the development cycle for the nearly completed Human Resources Service.

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WBBS Schedule Overview Not Started In Progress Complete Late

GO Requirements: AS IS Implementation Deployment LIVE Post 1/31 44 d 3/31 9/6 5/23 51d 8/4 8/8 23 d 9/9 Implementation Requirements: TO BE IV&V Audit 2/15 35 d 4/5 7/15 21.1 d 8/15 10/26 Design Prototyping Training Initial O&M 2/28 45 d 4/29 5/2 15 d 5/20 7/6 36 d 8/25 9/1 39.5 10/26 Human Resources Human

Mar-05 Apr-05 May-05 Jun-05 Jul-05 Aug-05 Sep-05 Oct-05 Nov-05 Dec-05 Jan-06 Figure 11.5. Implementation Schedule. Overview for Human Resources Service.

For each Business Service, a comprehensive set of contract deliverables must be produced and approved by NRAO‐led inspection teams or by the NRAO formal approval process. Figure 11.6 documents the twenty three deliverables produced and approved for the Human Resources Service.

Complete Late HR Deliverables Legend: < 2 Weeks > 2 Weeks

REQUIREMENTS

Done 2/25/05 HRM #1: "As Is” Process Flows Use Case Models Done 4/5/05 HRM #2: "To Be" Process Flows Use Case Models Done 3/9/05 HRM #3: Conversion Strategy Done 3/22/05 HRM #4: Testing Plan Done 3/2/05 HRM #5: Training Plan

DESIGN

Done 4/29/05 HRM #6: Prototype Configuration Complete Done 4/20/05 HRM #7: Prototype Test Scripts Done 5/20/05 HRM #8: Prototype Test Acceptance

IMPLEMENTATION

Done 7/28/05 HRM #9: HR Final Design - Identify/Notify Inspection Team of Submittal Done 8/2/05 HRM #9: HR Final Design - Distribute HRM Submittal to Inspection Team Done 8/4/05 HRM #9: HR Final Design - Inspection Complete Done 7/6/05 HRM #10: Draft Configuration Design Workbook Done 7/6/05 HRM #11: Final Report Matrix Done 7/6/05 HRM #12: Custom Technical Specifications Done 7/6/05 HRM #13: Security Design DEPLOYMENT

Done 7/25/05 HRM #14: Integration Test Scripts 8/8/05 HRM #15: Integration Test Acceptance - Identify/Notify Team of Submittal 8/11/05 HRM #15: Integration Test Acceptance - Distribute Submittal to Team 8/15/05 HRM #15: Integration Test Acceptance – Inspection Complete Done 8/4/05 HRM #16: Training Guide 8/22/05 HRM #17: Cutover Script 9/6/05 HRM #18: "Power User" Troubleshooting Guide 9/9/05 HRM #19: Cutover Punch List Complete 9/8/05 HRM #20: Data Conversion User Acceptance 9/9/05 HRM #21: Final Configuration Design Workbook 10/24/05 HRM #22: Post-Implementation Support Complete 10/20/05 HRM #23: Post-Implementation Audit Results - Identify/Notify Inspection Team 10/25/05 HRM #23: Post-Implementation Audit Results - Distribute Submittal to Team 10/26/05 HRM #23: Post-Implementation Audit Results – Inspection Complete

Figure 11.6. Contract Deliverables for Human Resources Business Service.

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To address the inability of the existing hardware infrastructure to support the WBBS implementation, an In‐Host/Out‐Host analysis and recommendation was performed and addressed with NRAO stakeholders. As a result of this, implementation of a new in‐house, Intel/NT‐based infrastructure was selected as the go‐forward strategy for the WBBS implementation and shown in Figure 11.7. This upgrade was completed in Q4 of FY 2005.

Figure 11.7. NRAO Architecture Upgrade to Support WBBS Implementation.

The PMO and NRAO stakeholders are also investigating migrating the NRAO Intranet / Internet to the Intel/NT infrastructure to reduce operations and maintenance costs and maximize efficiency.

Project Management Control System Initiative Overview

The objective of the NRAO Project Management Control System (PMCS) is to implement an enterprise level project management system that supports a common scheduling engine, browser‐based clients for accessing project data, and integration of budget and actual cost from the NRAO Accounting System with PMCS schedules. The PMCS supports a variety of users including Program, Project, and Control Account managers responsible for project success; Technical and Management members of each project team; and the Schedulers and Cost

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Analysts who develop and maintain schedule, budget, and cost in the PMCS as directed by management. Salient features of the NRAO PMCS include:

• Interfaces directly to WBBS • Program schedule support for NRAO projects and programs including: construction, development, operations, etc. • Critical path management • Common metrics (common dashboards, metrics detail) • Integrated cost and schedule management based on earned value project management

As depicted in Figure 11.8, the NRAO Common Standards and Processes define how the PMCS should be configured to produce standardized reports and metrics across the NRAO user base. All Observatory projects and programs will migrate to PMCS‐based Cost and Schedule systems.

NRAO PMCS USER BASE

ALMA GBT

EVLA EVLA-II

Common Standards & Common Reports & Processes Metrics

VLA VLBA

Other NRAO Projects and Programs

WelCom Solution Microsoft Solution

Figure 11.8. NRAO PMCS User Base Utilizes Common Standards and Metrics.

The PMCS initiative involves the acquisition, implementation, and operation of a Web Based, Enterprise level solution for the capture and reporting of program and project metrics for budget, cost and schedule. The PMCS implementation across all Observatory programs will meet the criteria defined by the Program Standards and Processes initiative and satisfy the reporting requirements for performing Program Management Assessments. The initial programs to utilize a PMCS solution at a standardized level of maturity for cost and schedule metrics in FY 2005 include ALMA and EVLA. All NRAO projects and programs will begin utilizing the PMCS solution after the initial programs successfully complete testing.

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Program Standards and Processes Initiative Overview

The Program Standards and Processes (PSP) initiative institutionalizes the methodology, processes, reporting, metrics, and standards for measurement and management of NRAO projects and programs. Examples of these standards and processes include:

• WBS Change Control Process • NRAO standards for reporting mechanisms, formats, and metrics • NRAO tailored PM process definitions based on the Project Management Book of Knowledge (PMI Standard for PM best practices) • NRAO tailored definition of OPM3 for PM Maturity Levels (PMI Organizational maturity model) • Risk management process • Subcontractor management process, etc. • NRAO tailored definition of the Earned Value Program Management (ANSI / EIA 748 Standard)

Program Management Assessments Initiative Overview

The Program Management Assessments (PMA) initiative for defines the approach for the assessment of NRAO projects, programs, and the Observatory‐wide project portfolio. This initiative defines the key role of the NRAO Program Management Office: perform periodic assessments using standardized reports and metrics that will provide early warning triggers to take corrective action. The PMA will be developed using an incremental, phased approach to maximize assessment capability consistent with the other Program Management Office initiatives.

The PMA Initiative involves the active participation of the Program Management Office in the review and analysis of all NRAO programs. In FY 2005, the Program Management Office also began monthly reviews of ALMA, and CIS. Standardized metrics will be captured by these programs and presented in Program Review format. Additional NRAO projects and programs will begin monthly reviews in subsequent quarters of FY 2006.

Key Objectives and Targets for the PMO Five‐Year Strategic Plan

Table 11.2 provides a summary of key objectives and targets for the PMO 5‐Year Strategic Plan.

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Table 11.2: Key Objectives and Targets for PMO 5‐Year Plan Initiative FY 2006 Targets FY 2007 Targets FY 2008 Targets FY 2009 Targets FY 2010 Targets WBBS • Payroll • Team WBBS WBBS WBBS Operational Calendaring Complete Complete Complete • ESS Operational Operational • Fiscal – G/L • Property Operational Management • Fiscal – AP Operational Operational • Travel • Fiscal – Job Cost Operational Operational • Business and IT Platforms Out‐ Hosted PMCS • PMCS • PMCS PMCS PMCS PMCS Operational with Operational Complete Complete Complete Focus Projects

PSP • Observatory at • Observatory at • Observatory at • Observatory at • Observatory at Standardized Measured Level Controlled Continuous Continuous Level of PM of Maturity Level of Improvement Improvement Maturity • Focus Groups at Maturity Level of Level of • Focus Groups at Controlled Maturity Maturity Measured Level Level of Maturity PMA • Add EVLA & • Observatory at • Observatory at • Observatory at • Observatory at PTCS to Focus Measured Level Controlled Continuous Continuous Groups of Project Level of Project Improvement Improvement • Focus Groups at Reporting Reporting Level of Level of Project Measured Level • Focus Groups at Project Reporting of Project Controlled Reporting Reporting Level of Project Reporting New • Continue • Continue • Continue • Continue • Continue Program Programmatic Programmatic Programmatic Programmatic Programmatic Development Support to All Support to All Support to All Support to All Support to All NRAO New NRAO New NRAO New NRAO New NRAO New Programs Programs Programs Programs Programs

In Q1 of FY 2006, implementation of the remaining WBBS High Priority Business Services will complete and enter the Operation and Maintenance (O&M) phase. Beginning in FY 2007 the remaining Business Services will be implemented including Team Calendaring, Asset Management, and Travel. Once O&M for all Business Services achieves stability as determined by a minimum monthly threshold of trouble tickets, the PMO will begin the process to Out‐ Host NRAO business and IT platforms.

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The NRAO PMCS system will be a key implementation target for FY 2006. Once implementation is complete, a focus group consisting of the PMO, ALMA, CIS, EVLA, and PTCS will transition schedule and cost reporting to the PMCS. In FY 2007, all NRAO projects and programs will be operational Observatory‐wide on the PMCS, budget allowing.

In FY 2006 Program Standards and Processes will be defined for the Measured Level of Maturity and put in practice by a Focus Group consisting of PMO, ALMA, CIS, EVLA, and PTCS, while the remaining Observatory projects and programs will execute at the Standardized Level of Maturity. In FY 2007, the Focus Group will move to the Controlled Level of Maturity, while the remaining Observatory moves to the Measured Level of Maturity. By FY 2008, all Observatory programs will be executed at the Controlled Level of Maturity.

Similar to the PSP targets for the strategic plan, Program Management Assessments will move through increasing levels of Project and Program Management Maturity with the Focus Group used to refine processes and best practices at each level before the remaining Observatory Programs move to that level of maturity.

Finally, the PMO will continue to provide programmatic and proposal support to all new Observatory programs.

Computing Infrastructure

Central Computing Services

Central Computing Services is coordinated by the Computing and Information Services (CIS) division. The mission is to plan an optimum computing and network environment for the users of NRAO telescopes, for the operation of those instruments, and for the development of new facilities. CIS sets policies and standards in this area, and coordinates relevant activities across the Observatory. CIS supervises the maintenance of all computer equipment and software observatory‐wide and maintains a budget to provide these services.

The sites and major projects (Green Bank, Socorro, ALMA) each have a computing division charged with providing local support and reporting to the local site director or project manager, as appropriate. Operational funding is provided through the sites and projects. CIS augments and coordinates the activities of the computing divisions. A key mechanism has been the CIS Executive Committee consisting of the heads of computing for the various NRAO sites and for the major development projects.

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Computing Security

The adoption of a solid computer security policy is a pre‐requisite to securing any enterprise from online threats. Since 1999, the NRAO has had in place such a policy, which provides a framework to balance the conflicting requirements of accessibility for the radio astronomy community and the public with the need for high security.

All of the NRAO operational sites are networked together. It is therefore essential that security be maintained at all sites; lack of diligence at one site will otherwise compromise the security at all sites. This is achieved through the security policy by a Computing Security Committee (CSC) composed of a Computing Security Manager (chair and CIS staff member), two representatives chosen by each of the four main NRAO sites, the chief NRAO network engineer, and Liaisons from each of Management Information System (MIS, business computing), the Safety Committee, and scientific staff.

The CSC has specified and implemented detailed practices to minimize security exposure. Since the implementation of these practices, there have been no serious computer security incidents. However, intrusion attempts, probes, viruses, spyware, and similar attack attempts continue to come from the Internet with a seeming exponential increase in frequency, scope, and sophistication. The threat from mobile and wireless equipment brought by visitors is widely acknowledged in the computer industry, and is also being addressed in the context of the committee and the security policy.

We will continue to improve education and documentation for NRAO computer users. We will maintain and enhance the security measures already in place. In addition, we will maintain Virtual Private Networking, which allows travelers and telecommuters to become part of the NRAO internal network securely.

Observatory‐wide Coordination

Computing Standards and Policy

To provide a uniform structure in which to carry out our mission, CIS will continue to develop and enforce standards, policies, and conventions originally formulated and adopted by its predecessors. Policies include Computer Use, Major Software Procurements, Computer Hardware Purchasing, etc. Standards include computer hardware configurations and lists of standard software applications.

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Common Computing Environments

The Common Computing Environment (CCE) is a major initiative started in 2000 to minimize the differences, often historic, in computing environments between NRAO sites. Such differences have in the past resulted in unnecessary incompatibilities, duplication of effort by computing staff, and confusion for users who work on systems at multiple sites. The CCE effort was renewed in 2002, reshaped into an ʹacceleratedʹ program, and this phase of the project was substantially complete at the end of 2003.

As computer environments are never static ‐ new versions of operating systems are released, new capabilities become widespread in the industry ‐ the coordination started by the CCE project is continuing through regularly scheduled meetings and online collaboration. This operational phase of the CCE will need to continue indefinitely.

Contracts

It is clearly advantageous that widely‐used software, such as office suites, computer‐aided design software, and operating systems are kept at the same revision throughout the observatory. This greatly simplifies document interchange and package support. A major activity of the CIS is to maintain contracts for such software. Further, CIS is responsible for maintaining contracts for key hardware components ‐ computers, printers, routers, etc. ‐ and for the frame relay intranet service. By consolidating licenses or equipment from multiple sites under a single budget, we reduce the overhead of managing these contracts, simplify the process of obtaining software upgrades, and can often negotiate better discounts with vendors. This amounts to approximately sixty contracts annually.

Digital Infrastructure

There have frequently been cases where the computer needs of the local computer divisions exceed their local budget. Traditionally, we have tried to make note of large new initiatives and to fund them from a separate, centrally‐administered budget.

Recurring Cost

Outside the construction projects, the NRAO has computer and associated equipment that is valued at roughly $2.4M. This equipment has a lifetime of no more than five years. Thus, a budget of no less than one‐fifth of this amount is required to address depreciation. The practice of maintaining a central budget for replacement equipment will be continued. This includes the whole spectrum of equipment from powerful systems for scientific visitors, servers, to desktop and laptop personal computers. At the desktop, when new equipment is acquired, it has been

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traditionally given to those who need the highest performance and trickle down the systems to less demanding users so that the oldest, slowest computers can be discarded.

Observations continue with the VLA, VLBA, and the GBT; data is written into the on‐line archive as it is observed. This means that we have the additional recurring cost of adding disk space to the archive regularly.

Coordinated Activities

We intend to continue the practice of maintaining a central budget to cover training fees for any computer professional at any site. To foster communication and collaboration between computing staff at the NRAO sites, we will provide funding for their inter‐site travel. This budget will be available to cover the travel expenses involved in bringing together a large number of NRAO computing staff involved in specialized computing fields such as real‐time development and system administration.

Information Infrastructure

Web Services

The existing web infrastructure includes a load‐balancing scheme for external access and mirrored information at each of the major sites. This has provided 100% uptime service to the community and the staff for the last few years. However, because of staffing, there has been no content management for the site, so some of the information is regrettably out of date. It is time for an overhaul. We intend to work with the Education and Public Outreach (EPO) Division to substantially improve the NRAO website in FY 2006.

Several instances of web‐based collaboration software known as a ʹWikiʹ have been created within the NRAO. This software has already helped individuals, groups, and projects within the NRAO to perform collaborative tasks including project management, reporting, and software development. We expect the growth of use of this collaboration in the coming years.

We provide two web‐mail interfaces permitting staff members to access their mail in a safe and secure way from any web browser on the Internet.

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Other Services

The NRAO has a unified calendaring system for scheduling internal meetings, colloquia, and other significant events. There are more modern tools available to us, but the conversion will take some time to implement. We will explore this in the coming year.

We have developed a common directory access protocol to provide accurate, up‐to‐date staff information, including a phone book, for the entire observatory. Although this works well, we will need to interface more closely with the employee self‐services that will be deployed in the coming year. Here too there are more modern tools available, so we will consider the cost of changing to new services.

Networking and Telecommunications

In the last few years, we have consolidated many of our long distance phone services under a single contract through the General Services Administration (GSA) Federal Telecommunication Service (FTS2001) initiative. In addition, we provide web meetings, audio conferencing, international and domestic toll‐free service, and calling cards to our employees under this program. This provides the most cost‐effective service available. However, prices and available features are changing constantly, so continuous monitoring of service contract options is necessary.

The Local Area Network (LAN) in Green Bank has been greatly enhanced in the past few years. However, the Ethernet switches that are the backbone of this LAN are aging. We propose to continue a program to replace and upgrade the units in FY 2006 and FY 2007. A major upgrade of the LAN in the New Mexico Array Operations Center is in progress in Socorro. When completed, this will provide Gigabit (Gb) service to all desktops. A similar project is underway in Charlottesville. All offices in the recently constructed areas are connected to the new central communications room. This includes copper connections and conduits through which fiber can be pulled in the future. All occupied rooms in the original building have also been re‐cabled; the rest will completed by the end of 2005.

Since 1996, the NRAO has had an intranet connecting most of its locations using a frame relay. Since 2001 the service has been provided by AT&T under GSA/FTS2001. This provides a reliable and secure backbone for all internal electronic communications between the locations. Since the requirements of the operations have grown since 1996, we regularly re‐evaluate the bandwidth provided to the various locations. Increasing the bandwidth is, in many cases, merely a matter of cost. Decreasing costs have enabled us to increase the bandwidth to some sites cost‐effectively in the last two years. Demands for bandwidth for video conferencing, improved access to the business computers, and the need to be able to transfer large datasets

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from Socorro and Green Bank have required increased capability. A major initiative to provide 20Mbps service between the major sites should be completed by mid‐October 2005.

Through a special grant in 1999, we were able to deploy a small video communication network between the major sites using the intranet infrastructure. Since then, we have procured equipment to increase the number of systems to thirteen, and we now routinely support concurrent video conferences. The video system is also widely used to relay scientific and technical colloquia throughout the observatory. However, the biggest remaining deficiency for interactive multi‐site video between the auditoria is the auditorium sound systems. These will be upgraded in the next year. There is also a burgeoning requirement for personal video systems. We have proposed funding for a sophisticated video hub to give us better management and diagnostic capabilities and to allow us to run conferences from a studio if needed.

The NRAO is a sponsored participant in the Internet2 from all major locations. There are also many increased network connectivity requirements for future operations: the need to serve data from the archives for the presently operating instruments (VLA, VLBA, and GBT), the full deployment of the GBT spectrometer, the opening of the Green Bank Science Center, the development of the North American ALMA Science Center in Charlottesville, the connectivity from Charlottesville to the operational sites in Chile, and the EVLA deployment.

Headquarters Computing

The NRAO Charlottesville Computing Divisionʹs mission is to provide the computing services to the local NRAO staff and scientific visitors to Charlottesville. The local groups served by the Computing Division include the Directorʹs Office, Education and Public Outreach, the scientific staff Business Services, the Central Development Lab (CDL), Human Resources, the business office, Charlottesville ALMA staff, the Program Management Office, and the Charlottesville‐ based software development staff. The support includes electronic mail, printers, central servers, centralized data storage, data backup services, software installation and support, computer configuration and procurement, remote access capabilities (dial‐up modems, etc.), web services, directory services, network management, phone service, and application software support.

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New Initiatives

In fulfilling its mission of designing, building, and operating large radio astronomical facilities, the NRAO plays a major leadership role in the global radio astronomical community. Typically, many years are required to define and develop a major new facility, so that it is appropriate to devote some of our resources to long term planning of facilities and instrumentation whose construction is not yet funded or possibly not even well defined.

Members of the NRAO staff are currently involved with a number of such new initiatives: the international Square Kilometer Array (SKA) project; the Long Wavelength Array (LWA); the Frequency‐Agile Solar Radio Telescope (FASR), the extension of VLBA baselines to space; the development of Focal Plane Arrays; and the characterization and mitigation of radio frequency interference.

The long term role of AUI/NRAO in these projects is not yet defined. It may be as a partner, as a member of a consortium or other collaborations, or as the leader. But, whatever our ultimate role, continued participation in these long‐term initiatives maintains and strengthens our leadership role, while at the same time enhances our ties with and fosters the health of the broader radio astronomy community. In addition, as a key source of both technical and scientific expertise, the NRAO serves as a valuable resource to the world‐wide astronomy community for both ground‐based and space‐based initiatives. At the same time, participation in these broadly based initiatives benefits the NRAO to the extent that it enables the Observatory to keep pace with and exploit technological innovation.

The Square Kilometer Array (SKA)

The Square Kilometer Array (SKA) is an ambitious international collaboration to develop the next generation radio telescope with a sensitivity up to two orders of magnitude better than the current VLA. The NRAO is a member of the U.S. SKA Consortium and is represented on the International SKA Steering Committee; these two bodies are charged with the coordination of national and international efforts, respectively, to define the scientific goals, specifications, siting, and technology for the SKA. The NRAO has been active in developing the scientific case for the SKA, in addressing the technical challenges presented by the SKA, and in organizing meetings to focus the attention of the U.S. and international radio astronomy community on the opportunities presented by the SKA. SKA activities at the NRAO, which are funded through the NSF‐AUI Cooperative Agreement, complement the planned activities of US SKA Consortium members.

The basic concept, size, wavelength coverage, location, and cost of the SKA are still very uncertain. However, it is becoming increasingly clear that a single design cannot provide the

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wide frequency range needed to address the full scope of scientific questions, especially if the SKA has multiple beams covering a wide field of view or is electronically steerable. Although the EVLA will provide a major improvement in sensitivity and resolution over currently available instruments at centimeter and decimeter wavelengths, it will have only limited capability below 1.1 GHz. An SKA operating below this frequency located on a radio quiet site is an attractive complement to the EVLA and might be technically feasible if promising developments in aperture array technology in Europe materialize. However, it may be prohibitively expensive to achieve a full SKA at centimeter wavelengths, or to obtain the desired wide field of view, so a more modest facility may be developed for these wavelengths. Such a facility could come about as a natural extension of the EVLA and the VLBA and is referred to here as the North American Array

During the past year, NRAO has been particularly active on the international level, and will host the March 2006 meeting of the International SKA Steering Committee in Socorro, NM. Various NRAO staff members are serving as members (previously the Chair) of the International SKA Science Working Group, on the International SKA Steering Committee, as Chair of the International SKA Operations Working Group, as Chair of the Systems Sub‐Group of the International SKA Engineering Group, and through membership in the International Simulations Working Group, (SWG). There has also been discussion of having NRAO provide a new Project Scientist, to complement the Project Director who is from Europe, and the Project Engineer, who is from Australia.

During the past year, NRAO staff were particularly involved in publishing the report of the SWG (New Science Reviews, Vol 48), defining a preliminary operation model for the SKA, evaluating systems designs for the SKA, and in understanding ionospheric calibration techniques for both the SKA and LWA, especially at low radio frequencies and longer baselines.

Much of the planned SKA technical development at NRAO is shared with the EVLA program. This includes wideband low‐noise receivers and feeds, an advanced correlator designed to minimize the impact of RFI, the use of broad‐band fiber optic transmission systems, configuration optimization, advanced data management and archiving techniques including multiple‐field calibration in the presence of non‐isoplanatic screens, non co‐planar and high dynamic range imaging, the effective use of data archives, and real‐time imaging from complex data acquisition. Indeed, the strength of NRAO in the SKA development program derives from our long experience in designing, building, and operating large complex interferometer systems.

A wide range of other development programs, including wide‐band‐low noise inexpensive feed‐receiver systems, and cost‐effective broad‐band long distance data links, are being discussed throughout the SKA community and were included as part of an SKA Technology Development Program (TDP) recently proposed to the NSF by the US SKA Consortium.

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Although no funding for NRAO was requested through the TDP, we have actively participated in the preparation and defense of the TDP proposal. While this proposal is still under consideration at the NSF, at this time it appears that there will be little if any NSF funds for SKA development in FY 2006, and at best, only limited support in following years. Due to the limited resources which have been available at NRAO, it has been difficult for NRAO to begin the tasks which were originally planned for the Observatory to complement the TDP.

With a constant level of funding we will continue our involvement with the international evaluation and design activities. With increased resources, with the help of outside contracts, we can begin the design and fabrication of a prototype high frequency receiver, the design and fabrication of prototype LO/IF systems, the evaluation of configurations for the SKA antennas, broad band signal transport and correlation, the development of FPAs, more research on interference mitigation, and further development of wide field high dynamic range imaging algorithms. Of particular interest is the development and partial implementation of the long distance broad band data links which will be needed for the SKA. In FY 2006 we would like to evaluate the opportunities available through commercial or semi‐commercial collaborations and to digitize the existing VLA‐PT link, with the goal of implementing by FY 2010 a real‐time broad band link to one or more of the intermediate spaced VLBA antennas such as North Liberty Iowa, or Kitt Peak, AZ.

The Long Wavelength Array (LWA)

Perhaps the last frontier in the electromagnetic spectrum lies at long radio wavelengths, where radio astronomy first began with the work of Karl Jansky and Grote Reber. Although the relatively poor resolution at meter and decameter wavelengths and the effects of ionospheric distortion have, until recently, precluded much attention to this part of the spectrum, wide‐field diffraction‐limited imaging at arcsecond resolution is now feasible. Over the past decade, 74 MHz (4 meter) receivers and feeds provided by the Naval Research Laboratory (NRL) have been installed on the VLA and have been used by many observers. But, the NRL system is limited to a single frequency, can only be used for strong sources, has limited dynamic range, and the resolution is limited to 10‐20 arcseconds. Nevertheless, with the success of the 74 MHz VLA system, there is growing interest in a dedicated array operating at meter and decameter wavelengths.

The Long Wavelength Array (LWA) is an ambitious plan for an array of fifty 100m diameter stations, each containing 256 dipoles operating from 10‐80 MHz and with baselines up to 400km. This telescope will provide NRAOʹs user community with a new, extremely powerful telescope with high resolution operating in this poorly studied spectral region.

The LWA is a joint venture of the Southwest Consortium (SWC, UNM, NRL, LANL and the University of Texas Applied Research Lab) and has received endorsement by the recent

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National Academy of Science (NAS) Decade Survey Committee. The SWC anticipates significant funding to complement the NRL funding already in place which will allow the construction of the full LWA. Discussions between NRAO and the SWC are underway to allow the SWC to implement this plan and to define NRAO’s role in the construction and operation of the LWA. Although NRAO is not a member of the SWC, we are represented in the LWA management meetings.

During this past year NRAO has worked with the SWC to develop the LWA concept. The first step will be to build a demonstrator station on the VLA site to be used together with the VLA to test the LWA instrumental concepts. NRAO staff are playing a major role as consultants in a number of areas of the project including management, the station layout design, the fiber transmission system, the correlator, interference testing, LNA/antenna design and testing, and the development of the imaging algorithms. The VLA technical staff is helping prepare the site for the LWA demonstrator station and to connect the station to the rest of the VLA.

In 2005 NRAO signed a Memorandum of Understanding with the University of New Mexico to cooperate with the SWC on developing the LWA. This process will continue in FY 2006. In FY 2006 NRAO also hopes to play a major role in prototyping a long distance fiber transmission system which will be needed to connect the stations in the final LWA. It had been anticipated that additional LWA stations would share fiber and other EVLA infrastructure, but it is not clear if these two projects will proceed on compatible time scales.

The Frequency Agile Solar Radio Telescope (FASR)

The Frequency Agile Solar Radio telescope project is an initiative of the solar‐physics community to build an optimally designed instrument to perform broadband imaging spectroscopy over a frequency range of ~0.1‐30 GHz. The project was ranked as the number one small project (<$250M) by the Decadal Review of the Solar and Space Physics Survey Committee of the NAS/NRC Space Science Board. The project has also been endorsed by the Decadal Review of the NAS/NRC Astronomy and Astrophysics Survey Committee as one of three solar projects for the coming decade: the Advanced Technology Solar Telescope (optical/IR), the Frequency Agile Solar Radiotelescope (radio), and the Solar Dynamics Observatory (optical/EUV/SXR).

FASR will probe the solar atmosphere from the chromosphere up to the middle corona. It is designed to address an ambitious science program, including coronal magnetography, the physics of flares, drivers of space weather, and the thermal structure and dynamics of the solar chromosphere. FASR will bring unique capabilities to bear on these problems, capabilities that are highly complementary to existing and planned ground‐ and space‐based facilities.

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Instrument development requires the participation of key personnel at the NRAO Central Development Lab and coordination with university partners. Project organization and management planning is a critical component of the FASR DDP and should not be delayed. A key activity is to organize the FASR Project Office under management by Associated Universities, Inc (AUI). The project office will be responsible for the FASR implementation plan and will comprise a partnership between the NRAO and university groups. Participating partners currently include the New Jersey Institute of Technology, U.C. Berkeley, the University of Maryland, and the University of Michigan. Hence, the FASR project under AUI management will include a strong university‐based component. Foreign partners will also likely participate in the project, notably Paris Observatory and ETH/Zurich.

Looking forward to FASR construction it is expected that, as a key partner in the FASR project, the NRAO will continue to play a leadership role in making this key new facility a reality. NRAO is leading the preparation of a proposal to the NSF for the design, construction, and operation of FASR. Earlier this year, a proposal was submitted to the Atmospheric Division of the Geosciences Directorate for the FASR Design and Development Plan (DDP). The FASR DDP requests funding in support of the myriad activities needed to prepare the proposal to construct and operate the instrument, including specification of FASR science requirements, the technical system block diagram and interface specifications, data flow diagram and software plan, a project Work Breakdown Structure and task implementation plan, identification of institutional participants, a detailed project organization and management plan, costing methodology and cost estimate, site selection, and operations planning. While NSF funding is anticipated, it is not expected to be forthcoming before early in the 2006 calendar year. This being the case, bridge funding may be required to continue FASR planning activities at the NRAO, particularly those associated with instrument development, and project organization and management planning.

Space VLBI

For more than twenty five years, the NRAO has worked toward extending interferometer baselines to space and to use space‐based facilities to facilitate data transfer. In the 1970ʹs we participated in experiments with the Canadian CTS satellite; in the 1980ʹs NRAO collaborated with a large international group in using the Tracking and Data Relay Satellite System (TDRSS) to extend VLBI baselines to more than 20,000 km and in the design of several (never funded) space VLBI initiatives. With NASA support, we played a major role in the design and operation of the Japanese VLBI Space Observatory Program (VSOP) through the development and operation of space VLBI capabilities on the VLBA array and correlator and the Green Bank tracking station, planning of the mission operational interfaces, and scheduling of observations. This effort was recently recognized by the International Academy of Astronautics which will present “The Laurels for Team Achievement Award,ʺ to the VSOP team including NRAO in

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recognition of extraordinary performance and achievement by a team of scientists, engineers, and managers in the field of Astronautics to foster its peaceful and international use.ʺ

Two space VLBI missions are under currently being discussed by the international radio astronomy community: VSOP‐2 and RadioAstron. VSOP‐2 is a Japanese initiative consisting of a single spacecraft with a 10‐m off‐axis parabolic antenna, observing wavelengths from 7 mm (43 GHz) to 6 cm (5 GHz), a data rate of 1 Gbps, and a planned launch early in the next decade. VSOP‐2 builds on the experience gained from VSOP but will have an order of magnitude more sensitivity and resolution than VSOP.

For more than twenty years, Russian scientists at the Astro Space Center have been working on the development RadioAstron, a space VLBI satellite operating at four wavelengths as short as 1.3 cm. Due to the deteriorating economic and political conditions in Russia following the collapse of the Soviet Union, progress has been frustratingly slow. Recently, however, the Russian space agency has expressed renewed interest in completing the RadioAstron spacecraft which now has the highest priority for all space‐based astrophysics missions in Russia. The official RadioAstron launch is set for October 2007. However, there are still significant technical and organizational hurdles to be overcome if RadioAstron is to be scientifically productive. Regrettably, little progress appears to have been achieved during the past year; progress reports have not been forthcoming from Russia, and communication has been lacking in substance.

NRAO staff members have been actively involved in the planning for both these international space VLBI missions. At a minimum, we anticipate the use, by the world‐wide community, of the VLBA, EVLA, and GBT antennas as ground elements of the earth‐space interferometers for both RadioAstron and VSOP‐2. In addition, the NRAO has developed considerable expertise in operating satellite earth stations and in correlating the complex data from earth‐space interferometers; and the NRAO has several antennas on the Green Bank site that can provide critical support of space VLBI missions or other astronomical satellite tracking programs, as opportunities arise. However, participation in these exciting opportunities through the operation of ground stations or the correlation of data will depend on substantial support from NASA.

Focal Plane Arrays (FPAs)

There is increasing interest worldwide in replacing the typical single feed‐receiver system commonly used at the focal point of large filled‐aperture radio telescopes with full‐sampling focal plane arrays (FPAs). These can synthesize a large number of simultaneous beams and thus greatly increase observing efficiency. In particular, implementation of FPAs could greatly enhance the power of the GBT at all frequencies where the science requires large area mapping or searches for objects such as pulsars or transient sources. Also, a beam‐forming array feed

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could solve the problem of instrumenting the EVLA with receivers that cover the important 0.3‐ 1.2 GHz frequency range without expensive modification of the feed support structure.

However, challenging technical problems need to be addressed before this type of array feed can have sensitivities comparable to current single‐beam receivers. Physical size, weight, and hardware reliability put severe constraints on array feed implementations, and the signal processing requirements can be comparable to those of aperture synthesis arrays. Research and Development (R&D) activities include simulations, experimentation, and development of enabling technologies. The effects of mutual coupling of closely‐packed array elements on correlated noise, array efficiency, and signal processing must be studied and verified. Array element/LNA units must be improved from their current noise temperatures of about 50 Kelvin to well below 10 Kelvin, very likely with new cryogenic technology. A hundred or more receiver units with analog‐to‐digital conversion and signal conditioning must be made small enough and of low enough power dissipation to put the signals on optical fibers for transmission away from the focal region of the reflector. Each fiber must accommodate hundreds of MHz of signal bandwidth from each array element. Other issues to be addressed include the sampling dynamic range required for adequate cancellation of spillover noise and RFI, the economics and performance of different beam‐forming architectures, and the shielding requirements of digital electronics near the array. Each critical development area must be carried from simulation through prototype before an astronomically interesting array can be deployed.

We are discussing a collaboration with colleagues in Canada on design and prototyping of array components and on beam‐forming aspects of FPAs that could facilitate efficient performance of the EVLA below 1 GHz. Although the Europeans are putting substantial effort into similar devices, neither they nor the Canadians are attacking the problems in the ways described above. FPA development is essential to and directly on the path to implementing larger production units that can be used on the GBT, the EVLA, and later other large radio telescopes such as the SKA. The NRAO has unique expertise in low‐noise receiver and signal processing technology which can be leveraged by an investment in modern simulation and design tools and young research engineering talent.

RFI Mitigation Research

The NRAO staff is continuing collaborative research on RFI mitigation techniques with engineering faculty and students at Brigham Young University (BYU). This activity is funded by two new NSF grants that began on October 1, 2004: MRI Grant No. 0420767 to the NRAO and ATI Grant No. 0352705 to BYU. We are now training students to participate in this work over the three‐year duration of these grants. Four papers based on this collaboration have appeared in refereed journals in the past year.

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Our emphasis is now on implementing successful RFI excision algorithms in real‐time hardware in a form that is routinely useful to astronomers. A digital engineer in Green Bank is developing firmware and a hardware interface for a PC‐based, Field‐Programmable Gate Array (FPGA) system with the immediate goal of blanking radar and airborne distance measuring equipment (DME) pulsed signals in the 960 to 1400 MHz frequency range of redshifted neutral hydrogen and hydroxyl molecule (OH) radiation from external galaxies. The efficacy of these blanking schemes has been demonstrated for integration times of several hours with off‐line data processing.

Research on new algorithms for different types of interference continues in parallel with real‐ time implementation. The main concentration at BYU is on signal processing of array feed signals for nulling continuous interference in the far sidelobes of reflector antennas, such as the GBT. BYU staff are constructing a prototype, modest sensitivity feed array in the 1.3 to 1.7 GHz frequency range, and NRAO is instrumenting the GBT antenna measurement facility for efficient multi‐element pattern measurements for testing this array. Signal processing research at NRAO is centered on adaptive cancellation of TV, cell phone, and other signals in the 300‐ 1000 MHZ range using a reference antenna to acquire a high quality sample of the interfering signal. A new antenna system is now being installed on the top of the GBT feed arm for this purpose. Both NRAO and BYU are upgrading their data acquisition capabilities for recording long stretches of fast‐sampled data. These data are processed with various experimental algorithms in general‐purpose computers.

The RFI mitigation research is complementary to the efforts at Green Bank and the VLA to maintain and improve the radio environments at these sites. For example, at the GBT the RFI data acquisition antennas serve the purposes of gathering research data, measuring and diagnosing locally generated RFI, and measuring signals generated by transmitters in the National Radio Quiet Zone. A program to verify and improve the accuracy of radio propagation models used in Quiet Zone administration will be coordinated with RFI research activities in a project underway to install a remotely controlled RFI measurement station at the top of the GBT feed arm.

Charlottesville Facilities

Charlottesville operations are now divided between three buildings on two campuses: (a) Stone Hall, a recently expanded building on Edgemont Road that was originally built by the University of Virginia to the specifications of the NRAO and has been leased from the University by NRAO / AUI since 1964; and (b) 38,500 square feet of commercially‐leased space in two buildings located immediately south of Ivy Road on a campus formerly know as the ITT complex.

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The general contractor performing the major Edgemont Road / Stone Hall construction and renovation, Martin / Horn, Inc, completed their work in April 2005, increasing the square footage at Edgemont Road from the original 27,400 square feet to 59,751 square feet. The NRAO facilities team carefully planned and executed the transition of Observatory personnel into their new facilities. All ALMA and Business Services personnel who had been temporarily deployed to the Old Ivy Commons leased facilities were moved back into offices at Edgemont Road, and some personnel were moved within the Edgemont Road building to better facilitate their work and Observatory operations.

Figure 12.1. The recently renovated and expanded NRAO Edgemont Road / Stone Hall facility is home to the North American ALMA Science Center, the North America – ALMA construction project, the Director’s Office, Observatory Administration, Education and Public Outreach, Program Management Office, and other Observatory‐wide service organizations.

Completion of the Edgemont Road construction and renovation provides the space needed to accommodate the North American ALMA Science Center (NAASC), the focal point for astronomical user support and further development of the North American component of ALMA Operations. This additional space is also accommodating the necessary growth of the NRAO Charlottesville Library, conference, and Archive facilities. The HVAC systems and communications infrastructure at Edgemont Road have been upgraded, yielding substantially improved fire protection and accessibility, and a safer, more efficient work environment.

The HVAC coolant piping replacement is a significant renovation task that is expected to occur at the Edgemont Road facilities in FY 2006. Final drawings and work packages are being produced by the A & E firm, Versar, Inc. These will be reviewed by the University of Virginia

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(UVA) Facilities Management, revised, and then transmitted to a professional construction estimator, whose detailed estimate is due in December 2005. This estimate will form the basis for a proposal to the UVA Provost, whose approval is required to fund this renovation from the NRAO maintenance reserve. This maintenance reserve is part of the on‐going UVA / NRAO lease agreement. Thus, if this HVAC coolant piping replacement is funded from maintenance reserve, as the Observatory has proposed to UVA, no additional funding is required. The anticipated construction scope is estimated to require six to eight weeks of work at Edgemont Road that would be conducted in spring 2006.

The Observatory’s commercially‐leased space on Ivy Road provides a synergistic environment for the development and production of ALMA and non‐ALMA electronics and technology by the Central Development Laboratory (CDL) scientists, engineers, and technicians. The CDL two‐building facility at Ivy Road is close to the Observatory’s Edgemont Road / Stone Hall facility and is, therefore, close to the NAASC. With the cooperation and assistance of the private landlord, these buildings were extensively modified in FY 2004 to accommodate the office and lab space needs of the CDL and ALMA, and are now well‐suited to the requirements of this specialized research, engineering, and development. As additional requirements are presented in support the ALMA construction project, the Observatory anticipates that some additional smaller‐scale modifications will likely be made to these buildings.

Figure 12.2. One of two commercially‐leased buildings that is home to the NRAO Central Development Laboratory.

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Spectrum Management

Spectrum management duties for the NRAO are carried out by the Charlottesville‐based Spectrum Manager in consultation with Green Bank and Socorro‐based RFI groups which monitor and mitigate RFI to the Observatoryʹs instruments. The Spectrum Manager is assisted on an occasional basis by current and retired staff members throughout the Observatory who have participated in spectrum management and RFI‐related activities in the past. NRAO staff scientists also participate in spectrum management as members of IUCAF (http://www.iucaf.org/) and CORF (http://www7.national‐academies.org/corf/).

Planned Activities for 2006

The Spectrum Manager participates in on‐going U.S. and international meetings of ITU‐R Study Groups SG 1 (ʺspectrum managementʺ) and SG 7 (ʺscience servicesʺ including astronomy and earth sensing).

Issues before SG1 having an impact on radio astronomy include broadband internet access over power lines, generation of solar power from satellites, implementation of ultrawideband devices (a technology which includes 24 and 76 GHz short range automobile radar and low‐ power use of the entire band 3.1‐10.6 GHz to achieve short‐range wireless data rates comparable to USB 2.0 ‐ 500 MHbs/s), use of the spectrum between 275 and 3000 GHz, and a series of studies of band‐sharing between radio astronomy and various satellite services.

The traditional radio astronomy group, Working Party 7D, is considering radio quiet zones, radio astronomy from space, a draft recommendation on band sharing between cloud radars and radio astronomy (see the discussion of CloudSat below) and several other items which will appear on the agenda for the next World Radiocommunications Conference (WRC), in 2007 as described below.

NRAO participation in such international activities assists the world‐wide radio astronomy community to further its agenda at the WRC: next is WRC07, to be held October – November 2007. Items of particular concern at WRC07 include a pair of L‐band fixed‐satellite feeder links, flanking the protected H I band, which the U.S. is pushing for a primary allocation and which the radio astronomy community is striving to constrain as much as possible, and new spectrum to be used for high data rate aeronautical telemetry, to be sited somewhere near the 4830 MHz H2CO line. More important matters may appear on the agenda for the 2010 WRC, namely, studies of radio quiet zones and allocations above 275 GHz (the current upper limit), probably up to 1000 GHz. The ITU is also beginning to consider extending the definition of radio spectrum above 3000 GHz.

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These international activities, and a liaison to CRAF (Europeʹs equivalent of our CORF), are fairly time‐intensive, requiring one or two days each month in telephone meetings as well as five to six weeks in face‐face ITU meetings each year, to say nothing of the amount of required reading, redacting, and, hopefully, writing (i.e. the constructive role of crafting new documents).

At the national level, the NRAO Spectrum Manager writes the NRAOʹs comments on FCC issues; recently, for instance, involving the use of cell phones on airplanes (which may inadvertently cause problems in the protected OH band), and use of the TV bands by unlicensed devices (which would have harmonic spurious emission in several protected bands). NTIA testing of BPL emissions is ongoing and the effect of such use on NRAO telescopes is very poorly understood (there being as of yet no practical experience). Unfortunately, the FCCʹs rules for use of BPL, when published this year, inadvertently confused the VLA (which uses 74 MHz) and VLBA (which does not).

The Spectrum Manager serves as a point of contact for the servicing of various MOU with Iridium (which seeks to implement a new aeronautical mobile service), Globalstar, ARINC, Boeing (which would like to outfit planes for broadband, except that airlines keep going bankrupt), and the like. Various FCC regulations require the assent of the Spectrum Manager in such matters as implementing helicopter video surveillance by police and emergency services. The Spectrum Manager also serves as the point of contact between the international radio astronomy community and the CloudSat 94.1 GHz orbiting (2 kW!) radar (http://www.iucaf.org/CloudSat/ ) due to launch in late 2005. This radar is the subject of a new draft ITU recommendation on band‐sharing, which was crafted by several NRAO staff. The prospect of CloudSat, whose radar would burn out any SiS junction which directly looked at it while mounted on a radiotelescope, inadvertently allowed the Spectrum Manager to achieve one his goals from the previous Program Plan. Increased participation in spectrum management on the part of mm‐wave observatories.

Within the Observatory, the Spectrum Manager makes site visits to discuss in‐house RFI and spectrum management activities. Of current concern for NRAO sites are the rollout of digital TV (which may have unfortunate consequences for experiments below 200 MHz), the rollout of BPL, the introduction of ultrawideband devices, increased use of Iridium handsets for aeronautical telemetry, geographic area licensing (under which NRAO does not have detailed knowledge of transmitter locations) and, overall, the trend toward proliferation of unlicensed, often portable, devices.

One set of goals for the coming year relates to implementation of the ALMA Radio Quiet Zone, which should serve as the model for an emerging class of protected regions: a quiet zone was also created recently around the GMRT and one will certainly be implemented around parts of the SKA. The existence of national radio quiet zones of this sort will, it is hoped, eventually be

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recognized at the highest level, based on a draft new question written at NRAO and submitted to WP7D of the ITU. A related issue is wider involvement of ALMA in spectrum management issues. As the largest radio observatory and the partner/operator of a radio quiet zone, such involvement is incumbent upon ALMA.

The Spectrum Managerʹs suggested plan for an ALMA office of spectrum management/RFI monitoring within the international project has been incorporated in the draft ALMA operations plan. Now, ALMA and/or NRAO must become involved in CITEL, the Inter‐ American group which represents Western Hemisphere (and, so, South American) interests most broadly at the ITU. CITEL is currently dominated by North American commercial interests, not always to the benefit of the passive services and the instruments hosted by various South American nations.

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Baseline and Mission Requirement Funding Plans

The FY 2006 baseline funding plan meets the Presidential Request Level of $47,400,000. This is an extremely tight budget given the breadth and complexity of NRAO facilities and the Observatory’s responsibilities to the astronomical community. When one‐time augmentations for special purposes (e.g., infrastructure renewal, GBT azimuth track repair) are excluded, the base NRAO operations budget has been essentially flat since FY 2001. During this time, the cost of goods and services as measured by the Consumer Price Index has increased by ~10%. To avoid losing further ground against market salaries, the NRAO has also instituted staff salary increases of order 3.5% per year during this period. Despite this program, recent surveys have shown that NRAO salaries are still ~10% below the average of comparable non‐profit research institutes and much more below the commercial market. The carry‐over from one fiscal year to the next, which serves as a reserve against a variety of possible financial emergencies, has dropped from over $2 million two years ago to under $800k in FY 2006. As a consequence of several years of flat budgets, the NRAO’s ability to operate its world‐class facilities—the GBT, VLA, VLBA, and soon, ALMA—has been seriously hampered.

The FY 2006 baseline budget follows on the heels of a particularly difficult FY 2005 budget that required a call for voluntary early retirement and transitions to part‐time employment. Thirteen employees accepted the early‐retirement offer and another five transitioned to part‐ time. In addition, a number of open vacancies may not be filled. The scope of some activities has been reduced to compensate for this reduction in force, but the Observatory has tried very hard to maintain its basic portfolio of observing capabilities and observer support. This has resulted in a great deal of stress on the staff, signs of which are evident. For example, the attrition rate in the last two months jumped from a nominal rate of ~5% to ~11%. The New Mexico Operations budget is at the same level for materials and services (M&S) as it was two years ago, and the overall Green Bank Operations budget is ~$500k lower than it was in FY 2004.

The FY 2006 baseline budget will cover basic telescope operations at the VLA, VLBA, and GBT plus the following high‐priority items:

Observatory software

• The EVLA data‐archiving system will be designed and early implementation will begin by the time the prototype correlator arrives in Q1 2007. • The NRAO Simple Image Access (SIA) service will begin operation.

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VLA

• The first of several modified EVLA antennas will be returned to the VLA for observing. • The number of operational VLA antennas will return to 25 or more before the end of the year. • The new on‐line proposal submission tool will debut at the VLA. • The pilot imaging project for the VLA data archive will be completed. • Approximately 3,500 railroad ties and one azimuth bearing will be replaced.

VLBA

• All ten VLBA stations will be upgraded to Mark 5 operation, accompanied by ten Mark 5 playback devices at the VLBA correlator. This should increase the fraction of time available for scientific observations from 50% to nearly 60%. • The St. Croix antenna will be repainted, and three other stations will receive maintenance visits.

GBT

• Production scientific observations at 7 mm wavelength will commence. • Construction of the “Zpectrometer” will begin. • The Caltech Continuum Backend will be commissioned. • Operation at 3 mm wavelength will begin with engineering tests of the Penn Array bolometer receiver. • Construction of the 3 mm coherent receiver will be completed. • Control of the pulsar “spigot” will be integrated into standard observing.

Instrumentation

• Low‐noise HFET amplifier production will meet EVLA receiver needs. • Designs of EVLA HFET amplifiers covering 4–8, 8–12, and 12–18 GHz will be completed. • New state‐of‐the art HFET amplifiers covering 60–90 and 75–115 GHz will be designed. • Measurements of 385–500 GHz and NbTiN SIS mixers and HEB mixers will be made. • The 2–4 and 12–18 GHz EVLA feeds will be designed and tested. GBT prime‐focus feeds for 300/600 MHz and 1.30–1.45 GHz will be developed. • The new Phase III spectrometer will be deployed at the Green Bank Solar Radio Burst Spectrometer.

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Management

• Web‐based business services will be operational for payroll, safety, and fiscal divisions. • Local area networks (LANs) at Green Bank, Socorro, and Charlottesville will be upgraded. • The EPO website will be substantially improved in FY 2006.

North American ALMA Science Center

• Initial operational and staffing requirements of ALMA and the North American ALMA Science Center (NAASC) will be met.

Items not Covered by the Baseline Budget

Observatory software

• Enhancements in e2e and development and participation in Virtual Observatory initiatives. The NRAO has only a small fraction of the staff required for a comprehensive program in these areas that would be comparable to that of other major observatories such as the Hubble Space Telescope, (HST) Chandra, or Spitzer.

VLA

• Adequate VLA railway and azimuth bearing maintenance. Although the baseline budget will allow a limited program of VLA railway and azimuth bearing maintenance, it is well below that required to meet recommended maintenance levels and to reasonably mitigate the possibility of unplanned downtime from failures in these areas. • Imaging archive. No funds are available for data analysts necessary to reduce images for the Virtual Observatory project.

VLBA

• Outfitting the High Sensitivity Array with Mark 5 Recorders. The baseline budget allows only for outfitting the native VLBA antennas with Mark 5 recorders, but not the High Sensitivity Array that includes other large dishes such as the GBT and Arecibo.

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GBT

• Effective staffing for the Precision Telescope Control System (PTCS) project for 3 mm operation of the GBT. Although the baseline budget will allow some prototyping of PTCS instruments and techniques, the budget is inadequate for a vigorous program to reach 3 mm operations. • Next generation instrumentation. It will not be possible to proceed in any significant way on preliminary design and development work for the GBT advanced instrumentation programs such as imaging cameras which would greatly enhance the scientific capabilities of the GBT.

Instrumentation

• Instrument R&D. The development program at the Central Development Laboratory (CDL). Instrumentation development has lapsed in recent years at the CDL owing to constrained budgets. Most of the activity at the CDL is presently construction oriented (ALMA development or HEMT low noise amplifier construction). This is seriously compromising the possibility for future scientific advancements in the field.

Management

• Program Management Control System (PMCS). The Program Management Office’s implementation of the full PMCS, which will allow improved project management techniques and tracking of metrics and milestones, will have to be deferred due to budget and resource availability.

Optimal Science Program with Additional Funding

As noted above, the baseline budget is extremely tight. Even basic operations and maintenance are compromised by this budget, and the possibilities for optimizing the scientific capabilities of NRAO facilities and better serving the astronomical community are even more difficult. In this section, we identify some specific improvements that could be achieved with a modestly enhanced budget. All of these are of direct benefit to the user community in terms of enhanced scientific capability, improved accessibility, preservation of the infrastructure, or improved management processes. These activities are either not possible at all with the baseline budget, or only in a much reduced version.

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Community Access and Ease of Use

The NRAO would like its facilities to be available to any astronomer whose science could benefit from radio data. The Observatory would also like for its data products to be available in an archive permitting easy reuse. These goals could be realized through the end‐to‐end (e2e) and Virtual Observatory efforts. These efforts are already underway to the extent possible with limited resources, but the program is presently operating at levels well below that needed to achieve reasonable goals. A full‐fledged program comparable to that offered by HST and planned for ALMA requires an addition of about 6 FTEs in the first year of development, rising to an additional 27 FTEs (equivalent to ~$3M in annual funding), including the required operational support staff. Intermediate plans that require less staff – but return fewer capabilities – have also been considered. To allow initial prototypes and tests, an initial program of ~2‐3 software developers for e2e (~$250k/yr) and one for Virtual Observatory and image archive development (~$100k/yr) would be appropriate.

Adequate Maintenance and Infrastructure Support

Tight budgets have caused maintenance funds to slip below an optimal level, which increases the probability of mechanical failures and unexpected, unnecessarily prolonged downtime. Specific examples are VLA azimuth bearings and rail line maintenance. Presently, the VLA needs to refurbish three azimuth bearings at a cost of $25k each ($75k total) to have an adequate stock of spares. Approximately 1‐2 bearings per year will need to be refurbished to stay ahead of predicted failures. The VLA also needs to replace railroad ties at a rate of 5000 / yr (as advised by an external consultant) to insure that the rail system is sound. This requires about $130k/yr in incremental funding increases. Although the GBT is planning a major repair of the azimuth track in 2007, expenses to maintain the existing track continue at the rate of ~$100k/yr. These expenses are presently coming out of the major repair fund, which is diminishing that account and may affect repair options. These on‐going expenses should be covered by the operations budget.

Student / Observer Support Programs

For the past two years, the GBT has offered a very popular student support program. Students who are successful in obtaining observing time on the GBT are eligible to compete for a stipend of up to $35k/yr, provided that certain qualifications are satisfied. About $200k/yr is presently budgeted for this program. The NRAO plans to expand this program in a very limited way to the VLBA in the coming year, at a level of about $100k per annum (included in the baseline budget). This program should be expanded to the VLA and EVLA, and broadened to include not only students, but general researchers. In this way, NRAO programs would be competitive with programs offered by NASA for HST, Chandra, and Spitzer. A proper program would

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require several million dollars per year, but a reasonable student program could be expanded to all Observatory facilities for as little as $500k/yr.

Scientific Capability Enhancement

The VLA, VLBA, and GBT are each state‐of‐the‐art, and the best in their class in the world. The facilities could be enhanced to dramatically increase scientific capability at a small fraction of their capital value. Examples follow:

High Sensitivity Array Conversion to Mark 5

The High Sensitivity VLBI array, which includes the VLBA, VLA, GBT, Effelsberg, and Arecibo, has greatly improved the sensitivity of VLBI. Outfitting the GBT and VLA with Mark 5 recorders would produce a further increase in sensitivity and better operational reliability and efficiency. Total one‐time cost: $150k.

Increased VLBA data rate to 256 Mbps

The sustainable data rate for the VLBA is 128 Mbps. Most VLBA observations now are “sensitivity starved” by the lack of available bits. Full implementation of Mark 5 permits a sustainable rate of 256 Mbps or even 512 Mbps. At present, NRAO has been able to afford only enough disks to support a general rate of 128 Mbps. Increasing the data rate to 256 Mbps requires doubling the supply of disks. The larger disk supply would enable the VLBA observing efficiency to increase to about 65% at 256 Mbps, thus increasing the sensitivity of most observations by a factor of 1.4, and also enabling much more use of observing at 512 Mbps for an additional factor of 1.4 gain in sensitivity. Total one‐time cost: $268k.

GBT Precision Telescope Control System (PTCS)

Through the PTCS project, the GBT intends to extend its operating frequency to 115 GHz, where it would have the largest collecting area and best sensitivity of any existing telescope in the world. The PTCS program has been successful in reaching fairly good performance to 50 GHz, and has demonstrated techniques that will allow operation to 115 GHz. The project is very starved for staff effort, and presently needs at least another three staff positions for software development and systems engineering. (Annual cost: $300k)

Advanced Imaging Instrumentation for the GBT

The scientific capabilities of the GBT could be greatly extended through the use of focal plane array technology, which could speed observing by a factor of 10‐1000. A number of specific cameras are possible, including a large format (~6400 pixel) bolometer camera for 3 mm, a

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MMIC spectroscopic array of ~100 elements for 3 mm, and a beam‐forming array for 1.5 GHz (see CDL request below). Realization of such imaging systems will be multi‐year endeavors and will likely involve collaboration with interested university groups and external laboratories. R&D money to begin investigations for the science and technology is needed, followed by commitments for the full project. (Seed investment for bolometer camera and MMIC array: $75k each for science case development and technology assessment.)

Technology Research and Development

The technology research and development arm of the NRAO is the Central Development Laboratory (CDL). The once‐vigorous R&D program at the CDL has been greatly diminished in recent years owing to budget pressure. Technology development is the foundation of advances in radio astronomy and requires an aggressive program. Areas that should be pursued include those described below.

Focal Plane Array Development

Coherent beam‐forming and MMIC arrays could increase observing speed for the GBT by factors of 10‐1000. The CDL has expertise in both of these areas. MMIC array development would likely be done as part of a consortium. Research in coherent beam‐forming arrays require technical R&D in close‐spaced antenna arrays; low‐noise, wideband integrated amplifier‐antenna elements; compact IF modules; large‐scale cryogenics; and complex, FPGA signal processing component firmware. The required R&D program costs are ~$200k/yr for the first year.

Wide bandwidth digitization

Digitizers with up to 6 GHz of bandwidth and 6‐8 bits of sampling are available for certain commercial applications but have not been developed for radio astronomy. It should be possible to bring radio astronomy technology up to the commercial state‐of‐the art with a goal of achieving 10 GHz Nyquist‐sampled bandwidths. Wideband digitization can lead to large simplifications of receivers and receiver transmission systems and allow digital signal processing to start earlier in the signal chain. These improvements could result in substantially improved observing capabilities and data quality. ($200k/yr in the first year of R&D)

Advanced Digital Correlators

Technology advances very rapidly for digital electronics such that NRAO correlators should be replaced on a timescale of 5‐10 years. New architectural and technology approaches have been developed since the present generation of correlators was built for the NRAO synthesis and single dish telescopes. To ensure that radio astronomy is taking full advantage of technological

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advances, a program in digital correlator architecture and techniques is needed for the GBT, ALMA, and for the future SKA. ($350k first year).

Enhanced Program Management Tools and Processes

With additional resources, the Program Management Office would be able to implement the initiatives as originally planned for FY 2006. The specific initiatives include the implementation and deployment of the NRAO Project Management Control System (NRAO PMCS), the Web‐ Based Travel and Property Management services, the PMO Program Management Standards and Processes (PSP), and the Program Management Assessments (PMA). The PSP and PMA initiatives are crucial to provide the framework for successful operation of the NRAO PMCS. (Additional cost above baseline assumptions: $1M.)

Mission Requirements Budget

As noted in the preceding, the baseline Presidential Request Level budget is extremely difficult. With even modest increases, the NRAO could significantly enhance the capabilities and services it offers the astronomical community. An alternative Mission Requirements Level budget is thus presented with the following components:

• A 3.5% inflation riser relative to FY 2005. Several years of flat base operations budgets have made it extremely difficult maintain staff salaries, required materials and services, and basic facility maintenance. • The development and operational initiatives described in the previous section. • A modest Director’s Reserve of $500k that allows some flexibility to meet unforeseen expenses and to take advantage of opportunities that may arise.

In recognition of the overall budget pressure on NSF Astronomy, these increments are modest and still fall well short of proposed activities. Nonetheless, they represent the most urgent operational needs and the development opportunities that would bring the most immediate scientific impact.

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Table 14.1 Cooperative Agreement NSF AST 0223851 Sources of New FY 2006 NSF Funds (in $K) President’s Request Level (PRL) Total New NSF SPO # Scientific Program Orders (SPOs) Funds ($k)

1 NRAO Operations, Maintenance, and Management 40,460 Extended Very Large Array 5,440 ALMA Operations 1,500 Subtotal New NSF Funds SPO-1 47,400

2 Atacama Large Millimeter Array (U.S.) 48,840 3 Research Experience - Teachers and Undergraduates 198 4 Green Bank Solar Burst Radio Spectrometer - 5 MRI - Real-Time RFI Mitigation and Instrumentation -

Total New NSF Funds 96,438

Table 14.2 NSF New Funding by Expense Element (in $K) President’s Request Level (PRL) Materials, Salaries & Total New NSF SPO # Scientific Program Orders (SPOs) Services & Travel Benefits Funds Equipment NRAO Operations, Maintenance, and 1 34,470 11,955 975 47,400 Management

2 Atacama Large Millimeter Array (U.S.) 11,773 35,708 1,359 48,840

Research Experience - Teachers and 3 - 196 2 198 Undergraduates 4 Green Bank Solar Burst Radio Spectrometer - Real-Time RFI Mitigation and 5 - Instrumentation Total new NSF funds 46,243 47,859 2,337 96,438

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Table 14.3 NSF Funds by Budget Category (in $K)

Prior Year Uncommitted New NSF Funds Total Available Commitments Available for Carryover of FY (PRL)* for Commitment Carried Over Expenditure 2005 Funds from FY 2005

NSF - AST Funded Personnel Compensation 34,900 34,900 34,900 Personnel Benefits 11,343 11,343 11,343 Travel 2,337 2,337 2,337 Material & Services 45,191 29,741 74,932 55,691 130,624 Corporate Office Indirect Costs/ 2,409 2,409 2,409 Management Fee Common Cost Recovery 258 258 258 Device Revenue - - Research Equipment - - Total NSF AST only 96,438 29,741 126,179 55,691 181,870

NSF non-AST Funded MRI - - 6 6 CISE 173 173 - 173 Education 78 78 138 216 Total NSF non-AST - 251 251 145 395

Total NSF 96,438 29,992 126,430 55,836 182,266

* Presidentʹs Request Level

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Table 14.4 FY 2005 Carryover (in $K) FY 2005 SPO # Scientific Program Orders (SPOs) Carryover ($k)

1 NRAO Operations, Maintenance, and Management 471 Green Bank Track Repair Augment 4,012 Green Bank Precision Telescope Control System 100 Green Bank Telescope Structural Inspection 275 Green Bank Telescope Student Support Program 57 Extended Very Large Array 1,878 Subtotal SPO-1 Carryover 6,792

2 Atacama Large Millimeter Array (U.S.) 22,301 3 Research Experience - Teachers and Undergraduates 197 4 Green Bank Solar Burst Radio Spectrometer 251 5 Real-Time RFI Mitigation and Instrumentation 199 Total FY 2005 Carryover 29,741

Table 14.5 Corporate Office Indirect Costs/ Management Fee (in $K)

Corporate Office Indirect SPO # Scientific Program Orders (SPOs) Costs/ Management Fee ($k)

1 NRAO Operations, Maintenance, and Management 1,024 1 Extended Very Large Array 122 1 Atacama Large Millimeter Array Operations 34 Sub-total SPO-1 1,181

2 Atacama Large Millimeter Array Construction (U.S.) 1,229 Sub-total SPO-2 2,409

NPF MIT/Lincoln Labs 43m Telescope Project 21 Total 2,430

Note: Corporate Office Indirect Costs/ Management Fee is applied to AST Funds only. No fee is applied to SPO-3, SPO-4, or SPO-5

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Table 14.6 Prior Year Commitment (in $K) Total New NSF SPO # Scientific Program Orders (SPOs) Funds ($k)

1 NRAO Operations, Maintenance, and Management 1,902 1 Green Bank Track Repair Augment 24 1 Extended Very Large Array 2,549 Subtotal SPO-1 Prior Year Commitments 4,476

2 Atacama Large Millimeter Array (U.S.) 51,091 3 Research Experience - Teachers and Undergraduates - 4 Green Bank Solar Burst Radio Spectrometer 7 5 Real-Time RFI Mitigation and Instrumentation 118 Total Prior Year Commitments 55,691

Table 14.7 NRAO Management, Operations, and Maintenance Detail (in $K) President’s Request Level (PRL) Materials, Salaries & Total New NSF SPO-1 Operational Function Services & Travel Benefits Funds Equipment

Observatory Management 3,731 2,719 239 6,690

Education and Public Outreach 326 (3) 21 343

Central Development Laboratory 1,001 314 19 1,334

Green Bank Operations 7,997 1,661 113 9,771

New Mexico Operations 12,147 3,816 217 16,180

Extended Very Large Array 3,485 1,852 103 5,440

Computer and Information Services 829 622 25 1,476

Division of Science and Academic Affairs 3,923 509 234 4,666

ALMA Operations 994 496 10 1,500

Total SPO-1 new NSF Funding 34,434 11,986 981 47,400

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Table 14.8 Non‐Programmatic Funding (in $K) Materials, Common Salaries & Total New Funding Source Grant Name Services & Travel Cost Benefits Funds* Equipment Recovery JHU CH-1 and Lunar Recon Orbiter 13 6 7 26 MIT/LL 140 foot telescope 276 430 10 251 967 - New Non-Programmatic Funding 288 430 16 258 993 Note: The above listed grants have been awarded or have been confirmed as being in the funding process.

* Reflects FY 2006 funds only and is based on the preliminary estimate of 36.2% CCR fee.

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Table 14.9 Observatory WBS (in $K)

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Table 14.9 (continued) Observatory WBS (in $K)

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Scientific Staff Research Activities

Cosmology, Large Scale Structure, Galaxy Formation, and Gravitational Lensing

A collaboration between the Smithsonian Astrophysical Observatory, Harvard University, and NRAO has been established to test, and eventually install, a VHF receiver system at the Very Large Array (VLA) operating between 180 and 200 MHz. This system has been designed to study the evolution of the neutral intergalactic medium (IGM) at the end of cosmic reionization (z = 6 to 7) through observations of the redshifted 21cm line of neutral hydrogen. The specific experiments planned are to image the cosmic Stromgrem spheres around the highest redshift Sloan Digital Sky Survey (SDSS) QSOs, and to determine the power spectrum of HI fluctuations during this epoch. The VLA‐VHF system could set the first hard limits on the IGM neutral fraction at the end of cosmic reionization.

The Westerbork Synthesis Radio Telescope (WSRT) and Australian Telescope Compact Array (ATCA) will be used to carry out a survey for 1667 MHz OH megamaser (OHM) emission from a complete sample of 32 ultra‐luminous infra‐red galaxies in the redshift range 0.23 < z < 0.45. The galaxies have been chosen based on their high far infra‐red (FIR) flux and lie at the high end of the OHM luminosity function, which is presently almost unsampled. The observations will test whether the probability of OHM emission increases with increasing FIR flux at the highest FIR luminosities and thus whether OHMs can be used to probe the evolution of structure formation. The Giant Metrewave Radio Telescope (GMRT) will be used to carry out targeted searches for OHM emission in a smaller sample of hyper‐luminous infra‐red galaxies at z ~ 1.4.

The Green Bank Telescope (GBT) Ka‐band and Q‐band receivers will be used to carry out a blind survey for millimeter‐wave (CO and HCO+) absorption toward a radio‐selected, complete sample of 107 sources. The survey will be sensitive to molecular absorbers in the redshift range 0.9 < z < 2.4. This is the first entirely unbiased survey for molecular absorption and should result in a significant increase in the number of redshifted molecular absorbers. It will, for the first time, allow an estimate of the probability of finding a molecular absorber per unit redshift interval as well as the cosmological mass density of molecular gas in the above redshift range.

The GBT and the GMRT will be used to carry out deep searches for HI 21 cm absorption in high‐ redshift damped Lyman‐alpha systems. In parallel, the William Herschel Telescope (WHT), Very Large Telescope (VLT), and Gemini telescopes will be used to carry out a survey for damped Lyman‐alpha absorption toward a radio‐selected quasar sample, to obtain new targets for follow‐up 21 cm spectroscopy. This is a long‐term program to try to understand the nature of and physical conditions in damped absorbers, the precursors of present‐day galaxies, and to thus probe galaxy evolution.

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High resolution HI 21cm, OH 18 cm, and optical spectra will be obtained for all known absorbers as well as objects detected in the above GBT and GMRT HI and CO surveys. The frequencies of these transitions have different dependences on fundamental constants like the fine structure constant; a comparison between the line redshifts in individual absorbers will thus allow a measurement of any evolution in these constants with time. This will be the largest sample of 21cm absorbers to be used for this purpose, resulting in far lower systematic errors arising from intrinsic velocity offsets between the optical, mm‐wave, and cm‐wave lines.

The GBT and WSRT will be used to obtain precision measurements of the redshifts of the OH 18cm lines from the z ~ 0.765 lens toward PMN‐J0134‐0931 and the z ~ 0.25 source PKS1413+135, respectively. The conjugate nature of the satellite OH lines in both these systems, implying that the lines arise in the same gas, will allow high sensitivity estimates of any changes in the fine structure constant and the electron‐proton mass ratio over a large look back time, unaffected by systematic effects.

A global Very Long Baseline Interferometry (VLBI) array will be used to map the four OH 18cm lines from the z ~ 0.25 source PKS1413+135. This array will use the European VLBI Network (EVN), the Very Long Baseline Array (VLBA), the GBT, and Arecibo. The observations will determine the kinematics of the absorbing/emitting region and whether the lines arise from a circumnuclear disk or from a cloud complex distant from the Active Galactic Nucei (AGN). The spatial structures of the main and satellite lines will be compared, to model physical conditions in the cloud complex. The high sensitivity and spatial resolution of the observations will allow a comparison between the redshifts of the satellite OH lines at every independent spatial location, allowing the determination of an independent measure of any change in the fine structure constant and the electron‐proton mass ratio.

The AGN PSK1413+135 (see above) is being studied with multi‐frequency data from the VLBA, the GBI, and the Radio Telescope Antenna (RATAN). An attempt will be made to detect possible rapid deceleration of the jet at the point this feature leaves the central engine by analyzing the detailed structure revealed in VLBA imaging and also by rapid flux density changes observed by the GBI at X‐band. The possibility of helical structure in the jet will also be investigated along with the spectral ageing of the jet.

The VLA will be used to examine a number of unusual galaxies, which although located in the periphery of the Virgo cluster (about 10 Mpc from the cluster center) are as HI‐deficient as those located within one core radius of the center of the Virgo cluster and other rich galaxy clusters. Their structure should help elucidate the ongoing evolution of these galaxies and provide evidence that a non‐negligible fraction of the late‐type galaxies that enter the cluster environment are already preprocessed by their interactions within the members of their group.

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Internal galaxy kinematics are being modeled based on GBT and GMRT data to better understand the physical connection between absolute brightness of galaxies and their measured neutral hydrogen line profile widths. This relationship is a key tool for determining cosmological distances, and it may be indicative of fundamental dynamical processes in the evolution of galaxies.

The GBT will be used to search for CO (1‐0) emission from several high‐z submillimeter galaxies, making it possible to trace the coldest (and perhaps most massive) components of these systemsʹ molecular interstellar mediums. These measurements will help paint a more complete picture of the evolutionary state of submillimeter galaxies, which may represent the progenitors of the most massive spheroids in the local universe.

Scientists will continue to use the NRAO telescopes to study the formation of galaxies and supermassive black holes to the very highest redshifts, into the epoch of cosmic reionization (z > 6). The unprecedented sensitivity and spectral bandwidth of the GBT at 20 GHz and above allows for sensitive searches for molecular line emission (CO, HCN, etc.) from the most distant galaxies, thereby constraining the total molecular gas content – the fundamental fuel for galaxy formation ‐‐ of the first galaxies. The VLA then provides sub‐arcsecond imaging of the gas distribution, thereby constraining the dynamical masses of the systems, and providing direct images of the process of galaxy formation. The VLA also allows for imaging with arcsecond resolution and microJy sensitivity at 1.4 GHz. Such observations reveal the non‐thermal emission associated with star formation, thereby providing a dust‐free estimate of the massive star formation rate in the earliest galaxies.

On much larger scales, star formation and starbursts mold the appearance of galaxies. Apparently, star formation proceeded at much higher levels in the distant Universe than occurs at the present epoch. Simulations of the appearance of the deep millimeter/submillimeter sky as viewed by the Atacama Large Millimeter Array (ALMA) and by the GBT will continue as part of efforts to construct the former and to instrument the latter with high frequency receivers. The GBT will be used to measure CO emission from a sample of galaxies at intermediate z, taking advantage of its broad spectral coverage and great sensitivity to prove its usefulness as a redshift machine.

The GBT will be used to study carbon monoxide (CO) emission in high‐z molecular emission galaxies (EMGs). The CO (J=1‐0) transition will be observed to help establish molecular emission spectral energy distributions for known EMGs. Searches will be made for this CO line in a sample of candidate EMGs.

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Studies of dense molecular gas in high‐redshift galaxies through observations of hydrogen cyanide (HCN) emission in the J=1‐0 transition will continue at the VLA and GBT. The Institut de Radioastronomie Millimetrique (IRAM) interferometer will be used to search for HCN emission in higher J transitions.

The VLA is a fundamental contributor to the COSMOS project. The COSMOS program is the definitive study of galaxy evolution as a function of cosmic environment, and it includes Hubble Space Telescope (HST) imaging of 2 square degrees in the i‐band, corresponding to the largest single HST time allocation. State‐of‐the‐art observations are being made of this field at all wavelengths. The VLA provides microJy sensitivity observations at arcsec resolution at 1.4 GHz of the full field. These data, in combination with observations with the Max Planck Bolometer Array (MAMBO) at the IRAM 30m telescope, will be used to study the dust obscured star formation history of the Universe out to z = 3, as well as to identify luminous starburst galaxies back into the age of cosmic reionization, z > 6. The VLA‐COSMOS large program is a collaboration between astronomers at NRAO and at several institutes in Germany.

As part of multiwavelength collaboration, the VLA is being used to carry out a deep survey of the Chandra Deep Field South (CDFS) X‐ray field which includes the Hubble Ultra Deep Field (HUDF). While the HUDF reaches an unprecedented sensitivity limit fainter than mag 29, the remainder of the CDFS is covered by the HST Advanced Camera System (ACS) and Spitzer Great Observatories Origins Deep Survey (GOODS) programs as well as ground‐based OIR imaging and reaches mag 25 to 27. The unique combination of the most sensitive radio, X‐ray, and OIR imaging will give new insight into the formation and evolution of star formation and black holes as they are manifested by quasars and AGN, and in particular, will provide a better understanding of the relation between the formation and evolution of black holes and stars.

The GMRT will be used to obtain a deep 327 MHz image of the CDFS. When combined with a deep ATCA L‐band image, this will allow the detection of ultra‐steep spectrum sources in this field, down to an L‐band flux density of ~ 75 microJy, far below current flux thresholds. These sources are believed to be the best candidates for the highest redshift radio galaxies; the observations will thus determine whether a hitherto undetected population of faint radio galaxies exists at high redshifts.

Existing deep VLA observations of galaxy clusters will be paired with new ultraviolet data from the Galaxy Evolution Explorer (GALEX) satellite to compare active galaxy populations. This will provide insight into the importance of dust on star formation indicators and underscore the value of multiwavelength campaigns which include radio observations.

The possible link between the dynamical states of clusters of galaxies and activity in their members will be addressed using radio data along with spectroscopy obtained from the SDSS. Sensitive VLA observations have suggested that clusters involved in the coalescence of

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substructures have increased numbers of radio sources; however, detailed cluster dynamical assessments are often lacking. The SDSS provides hundreds of galaxy spectra per cluster out to redshifts of z ~ 0.2, allowing direct testing of cluster dynamics as well as optical classification of radio‐selected galaxies.

A very deep VLA 20cm observation using the A, B, C, and D array configurations will be used to study the nature of the microJy radio population and the evolution of star‐formation and black‐hole‐driven activity. The radio survey is the deepest radio image yet with an rms noise level of ~2.7 microJy. The radio survey covers a special region of the Spitzer SWIRE Legacy survey in the Lockman hole. A variety of optical/NIR imaging and spectroscopy and an X‐ray survey have also been assembled in this region to exploit these data. Follow‐up optical/NIR imaging and spectroscopy will also continue using several telescopes on Mauna Kea to clarify the redshift distribution of the faintest sources.

A deep 90cm radio survey with the VLA will be used to determine the low‐frequency radio spectra for the deep 20cm SWIRE field.

The 90cm radio image should be deep enough to detect a significant fraction of the faint, dusty z > 1 galaxy population at such a low‐frequency for the first time. Signatures of free‐free absorption as well as a faint steep‐spectrum population, which is expected due to Inverse Compton losses, will be investigated.

Recent developments in imaging algorithms will allow the re‐processing of a deep (12 hour) continuum observation of the Mitchell‐Condon field (J1300+306) at ~320 MHz obtained with the VLA in the A configuration in 1996 during a period of minimal solar activity and low RFI. Preliminary tests show that ionospheric correction will allow a sensitivity of ~0.25 mJy/beam across the field and should allow the observation of the knee in the number counts at this frequency in addition to lead to the identification of unusual sources, a number of which should be located at high redshift.

The VLA and VLBA will be used to carry out follow‐up observations of candidate gravitational lens systems discovered in the Cosmic Lens All‐Sky Survey (CLASS), and to study the properties of the lensing galaxies such as dark matter distribution in the cores. A series of observations is being undertaken to use the VLBA to find and/or place limits on the existence of so‐called ʺcore imagesʺ in lens systems, which is a sensitive test of the gravitational potential in the lensing galaxy core.

The propagation of gravitational radiation subject to gravitational lensing will be investigated. Gravitational lensing in an inhomogeneous medium can randomly amplify or de‐amplify signals from sources of gravitational radiation, and multipath propagation effects can, in principle, smear the signal arrival time. Both distortions have implications for the future

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generation of gravitational wave detectors because current signal recognition algorithms rely on matching the observed signals to templates only based on models of the emission. In collaboration with several university groups, the Cosmic Background Imager (CBI) will be used to measure the temperature and polarization angular power spectrum of the Cosmic Microwave Background radiation (CMBR) as well as to measure the Sunyaev‐Zeldovich Effect (SZE) in clusters of galaxies from the ALMA site in Atacama, Chile. Powerful data analysis techniques with which to analyze interferometric observations of the CMB and the SZE will continue to be developed.

CBI SZE observations of a complete sample of low‐redshift galaxy clusters have been obtained and are in the process of being analyzed. The CBI is well‐suited to make measurements in the ℓ range where the polarization power spectrum is expected to peak (ℓ ~ 900), and interferometry is a proven method to make these measurements. The CBI SZE work will extend studies previously done on objectively defined cluster samples with the Owens Valley 5.5‐meter telescope as well as the CBI, and aims at an improved measurement of the cosmic distance scale.

The GBT will be used to make measurements of discrete source foregrounds to the CMB in the 26 to 40 GHz frequency range. These measurements will employ a new 26 to 40 GHz receiver as well as a new continuum backend which is under construction. The work will initially focus on characterizing the total intensity properties of the discrete source foreground. The accuracy of 30 GHz measurements of CMBR anisotropy at all scales will be significantly improved by the GBT data, but the impact will be particularly notable on small scales (ℓ > 2000).

The dust emissivity of UV‐selected sources to z ~ 1.5 will be evaluated by a comparison of rest‐ UV GALEX imaging and 1.2mm MAMBO imaging of the New Technology Telescope (NTT) Deep Field.

The Survey of a Wide Area with NACO (SWAN) will study faint, compact, red sources through a program of AO‐assisted K‐band imaging at the diffraction limit of the ESO VLT. Deliberate selection of bright, blue natural guide stars at high Galactic latitudes makes it possible to build up a large area coverage using a ʺdiscrete deep fieldʺ approach.

Radio Galaxies, Quasars, Active Galaxies, and Gamma‐Ray Bursts

The VLA will be used to study the radio afterglows from gamma‐ray bursts (GRB). This is part of a large, multi‐wavelength effort at gamma‐ray, X‐ray, infrared, submillimeter and centimeter radio wavelengths. Most of the bursts will be detected by the Swift mission, a recently launched NASA satellite designed to detect ~100 bursts per year at gamma‐ray, X‐ray and optical wavelengths. Some of the goals of this work are to understand the nature of GRB progenitors

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(including the mysterious short bursts), constrain the energetics of the explosion and the compact central power source, and to use GRBs as a probe of the early Universe. The VLA will play a vital role in the Swift ground‐based follow‐up effort. Bright, nearby bursts will be observed with the VLBA in an attempt to resolve these superluminally expanding sources.

The GBT and VLBA will be used to investigate water megamaser systems in active galaxies. Water vapor masers provide the only means of spatially imaging the accretion disks in AGNs. Having recently used the GBT to identify a dozen new maser galaxies, investigators will next use the VLBA to image and model those sources in which the masers appear to be associated with the accretion disk, based on evidence from GBT spectroscopy. GBT monitoring will complement the VLBA imaging observations. Masers in an accretion disk are used to study the disk geometry and dynamics, the central black hole, and in some cases they can be used to measure a distance to the galaxy independent of standard candle assumptions.

The recent GBT detection of a water maser at z = 0.66 suggests that megamasers can even be used as direct probes of cosmology, with potential to confirm the prevailing model of Dark Energy. The GBT will be used to identify possible new maser disk candidates at cosmologically relevant distances.

The VLBA has been used at 5.0 GHz to obtain phase‐referenced images of faint radio sources in the National Optical Astronomy Observatory (NOAO) Deep Wide‐Field Survey (NDWFS) in the constellations of Bootes and Cetus.

The VLBA survey is complete in the 9 square degrees of the Bootes field and half complete in the 9 square degrees of the Cetus field. The investigators will complete the VLBA survey of the NDWFS by observing the remaining half of the Cetus field. When complete, this VLBA survey of 156 faint sources will have detected about 40 percent and failed to detect about 60 percent. In combination with data from the NDWFS and from Chandra and Spitzer, both the VLBA detections and nondetections will constrain the spectral energy distributions of 156 active nuclei. This final set of VLBA images in the Cetus field will also add to the tally of sources showing elongated structures on parsec scales or marking optically‐obscured active nuclei.

The role of black holes and relativistic jets in the formation and evolution of radio galaxies and quasars is only barely understood. Repeated VLBA observations of changes in the structure and polarization of radio jets made over a period of many years is tracing out the kinematics of the outflow and the role of magnetic fields in defining the acceleration and collimation of jets and how they depend on the local environment and black hole mass. The impact of these studies will be greatly enhanced with the launch of Gamma‐ray Large Area Space Telescope (GLAST) which will give contemporaneous information on gamma‐ray emission.

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The VLBA will be used to observe at 2 and 8 GHz 675 new sources which, together with the previous VLBA Calibrator survey observations of more than 2500 AGN, will produce a complete and homogeneous sample of compact sources north of declination ‐30 degrees with integrated VLBA flux density > 200 mJy. Completeness of the sample and uniformity of the data reduction will permit robust statistical analysis of this population of bright compact flat spectrum sources, such as: (1) population modeling of the observed core brightness temperature to estimate distributions of the intrinsic core brightness temperature, the viewing angle, and Doppler brightening; (2) expanding the cosmological significance of core‐jet angular size versus redshift distribution; (3) comparing the compactness of radio structures with intraday variability properties; and (4) correlating the radio core properties with optical class. Sources found suitable for phase referencing will be added to the VLBA Calibrator List and will significantly increase the sky density of phase calibrators.

The VLBA is being used at frequencies from 1.6 ‐ 86 GHz to attempt to discern the three‐ dimension structure of gamma‐ray blazar jets, via measurements of variation in component proper motion, linear polarization (magnetic field) structure and radiative transfer effects (e.g., Faraday rotation). Typically, the lower‐frequency observations (< 10 GHz) have insufficient resolution to adequately resolve the transverse and longitudinal structure of these jets and higher‐frequency observations lack sufficient surface‐brightness sensitivity to detect more than just the brightest of the jet components, which quickly fade as they move out. Thus, at any single observing frequency, it is difficult to develop a complete geometrical and evolutionary model of the jet material and the components (shocks) which move through them. It is desirable, therefore, to synthesize jet models from the widest possible range of frequencies. Together with isolation of stationary components (including the observed ʺcoreʺ at each frequency), the measurement of component motions (apparent velocities and accelerations) over greater distances along the jet should yield clues about the jet structure in three dimensions. The high level of aberration in these well‐aligned jets should show polarization degree and orientation effects which correlate with the geometrical picture and thus strengthen the models. Finally, better geometrical models of these jets will yield higher confidence physical and phenomenological deductions, including optical and Faraday depth, magnetic field order, gamma‐ray emission origins, dependence of jet properties on optical identification, etc.

The High Sensitivity Array (HSA) currently is being used to image a selection of radio quiet quasars (RQQs) on milliarcsecond scales to search for compact radio jets with identifiable knot components in their jets. In the next year, those sample members containing compact jets will be identified and will be the subject of proposals for multi‐epoch monitoring. The ultimate goal of this program is to determine whether RQQ jets undergo relativistic motion like their radio‐ loud counterparts. The results will distinguish between two variants for unified schemes of active galactic nuclei: one in which RQQs are like their radio‐loud counterparts with the jets observed at larger angles to the line of sight, and another in which RQQs and radio‐loud

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quasars are distinguished by having an intrinsically different fraction of their luminosity going into emission at radio frequencies.

The VLBA will be used to initiate a milliarcsecond polarimetric imaging survey of approximately 1,000 blazars, many of which are expected to be detected as gamma‐ray sources by the GLAST after launch in 2007. This survey will be used to establish a comprehensive statistical sample of jet properties that may be correlated with gamma‐ray emission properties to constrain the models for gamma‐ray production. The set of standard images, together with optical determination of the blazar redshifts, will be made available to the community for other studies. The VLBA images also will serve as reference images for blazars that GLAST finds to have particularly interesting properties, such as exceptionally high luminosity or extreme variability.

Studies of the continuum emission, HI absorption, and OH megamasers in ultra‐luminous infrared galaxies will continue. Such observations require both high angular resolution and extremely high sensitivity, achievable only by combining the VLBA with several large‐aperture instruments in the HSA. The objects of study, among the most luminous in the universe in the infrared, are generally believed to result from mergers and/or close encounters between galaxies. Previous observations currently being analyzed, and planned future observations, will improve the understanding of the merger process and how it may lead to a starburst or to the formation of one or more active nuclei.

Dynamical searches for intermediate‐mass black holes (IMBHs), with masses of a thousand to a million times that of the Sun, fail beyond the Local Group and are being replaced by AGN surveys. The AGN in NGC4395, a nearby Sdm galaxy, is a strong candidate for being an IMBH. So far, this AGN is the only candidate IMBH detected in the radio regime. At 1.4 GHz, the VLBA recovers about one‐third of the point‐like signal detected with the VLA in its A configuration. Imaging the missing 1.15+/‐0.16 mJy requires the HSAʹs high sensitivity and short baselines at 1.4 GHz. Being influenced by optical, UV, and X‐ray hints of outflows from this AGN, the primary HSA imaging goal is to search for jet‐like emission on scales of 0.2‐8.0 pc with almost ten times the VLBA sensitivity. Also, the AGN is located at the center of an HST star cluster with a half‐light diameter of 7.2 pc, so the secondary HSA imaging goal is to search for nonthermal emitters from the cluster to help with the HSA/HST registration.

Mrk231 is the nearest broad absorption line (BAL) QSO. Competing models for the BAL outflow invoke either an equatorial wind or a bipolar outflow. Generally, these models cannot be directly tested because structures inside the nominal 1 pc sublimation radius of the molecular gas in BAL QSOs cannot be resolved. But for Mrk231, the VLBAʹs sub‐milliarcsecond (MAS) resolution can trace the geometry of the central engine. There are claims that the H‐ alpha and BAL outflows in Mrk231 are one and the same, and emerge from the polar regions, not the equatorial regions, of the accretion disk whose spin axis is defined by the VLBI double

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spanning 1.1 mas (0.9 pc). To build on the prior results for the radio outflow traced by this double, new VLBA observations at 15, 22, and 43 GHz will be carried out. The imaging goals are to search for substructure in the outflow, refine understanding of the role of free‐free absorption toward the outflow, and improve constraints on the slow proper motions in the outflow.

The VLBA will be used to study the dynamics of the base of the jet in M87. At 43 GHz, the VLBA apparently just resolves the collimation region of the jet and is able to resolve side‐to‐side structures only a short distance farther out. As a result of its relative proximity, high flux density, and high mass black hole, M87 is the best source for such a study of a jet base on small scales relative to the gravitational radius. The VLBA will be used to determine the rates of motion of features close to the core in order to determine an appropriate frame rate for a movie. It is likely that previous observations have been seriously undersampled. Once the frame rate, perhaps as fast as every few days, has been determined, a movie will be made to study the evolution of jet features.

Analysis continues of data from an effort to follow up previous observations of free‐free absorption of the counterjet in 3C84 by attempting to observe molecular absorption in lines near 15 GHz. Because the free‐free absorption is only observed against the counterjet, and not the near side jet, the material is assumed to be in, or associated with, the accretion disk on milliarcsecond (parsec) scales. Meanwhile, an effort to observe time evolution of the free‐free absorption is also being analyzed.

The relatively nearby superluminal source, 3C120, continues to provide important constraints on jet physics. This jet is observed at radio, optical, and X‐ray frequencies and, in the radio, can be studied over a very wide range of scales. Previous theoretical analysis of helical instabilities in the inner few parsecs of the jet and an analysis of the implications of X‐ray detections of features on kiloparsec scales have provided constraints on the physical properties of the jet. The current work is focused on an attempt to determine the structure of the jet in the transition region between parsec and kiloparsec scales using a 327 MHz VLBA observation involving on the order of 100 hours of telescope time. The inner jet, and the knot at 4 arcseconds (2 kpc) are detected and show pronounced small scale structure.

The nature of a new population of very large FR I galaxies will be studied using a sample of B2 radio galaxies and existing, low resolution VLA images.

New images of Cen A at 90cm will be compared with GALEX and other images of the galaxy to look for connections between the radio structure and evidence for star‐formation from the UV image.

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Observations made with the GBT will be combined with higher resolution VLA data to study the energy losses of relativistic electrons in the outer regions of several powerful radio galaxies.

X‐ray observations of some galaxy clusters indicate the presence of cooled gas in the cores of some galaxy clusters and recent 12CO observations demonstrate the presence of molecular hydrogen in some of these cores. The amount of neutral hydrogen is much less than the total amount of cooled gas. Some models predict that a fraction of this core gas would be in the form of neutral hydrogen. The GBT will be used to observe neutral hydrogen from two cooling flow clusters.

New Spitzer Space Telescope observations aimed at imaging the resolved infrared emission from a number of well‐known radio jets and hotspots (e.g. 3C273, Cygnus A) will be carried out. These data will be combined with Chandra X‐ray Observatory, HST, VLA, Multi‐Element Radio Linked Interferometer Network (MERLIN), and VLBA data to constrain jet models and to study particle acceleration in the hotspots.

Deep Chandra and VLA images of a number of well‐known quasar jets are being obtained and analyzed including the deepest X‐ray image yet of a quasar jet (over 2 days exposure). These observations are aimed at detailed studies of the particle acceleration processes responsible for the radio to X‐ray emission.

One of the longest continuous monitoring programs being carried out by Chandra to follow morphological and spectral changes in the jet of the well‐known radio galaxy Virgo A will be continued for a fifth year. Coordination with the HST, VLA, and VLBA will be continued.

Jet emission from a sample of the highest‐redshift quasars have been discovered using archival and new VLA data. Follow‐up Chandra X‐ray imaging will be proposed for the longest and brightest radio jets to test models for the production of X‐ray emission in quasar jets and to set constraints on key physical parameters of the jets (speed, magnetic field, particle content).

Work continues on understanding the extremely bright (super Compton) emission from intra‐ day variable sources. These studies take advantage of the technique of Earth Orbital Synthesis (EOS), whereby the Earthʹs changing velocity with respect to the interstellar scattering medium responsible for the variations can be used to build a two‐dimension microarcsecond `imageʹ of the source. EOS will be used to probe the structure and dynamics of a number of intra‐day variable sources, including J1819+3845, PKS 1257‐326 and PKS 1519‐273. The last of these three sources exhibits an extremely high (4%) degree of circular polarization in one of its scintillating components, and this polarized emission is intrinsically variable on timescales of a year. The evolution of the circularly polarized emission will be investigated as a means of elucidating its origin.

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Normal Galaxies

NRAO instruments will be used to investigate the nature of Ultracompact Blue Dwarfs (UCBDs), the smallest members of the class of Blue Compact Dwarfs. These systems have very low metallicity, total sizes of a few 100 pc and masses <108 solar masses, making them candidate galactic building blocks. High‐resolution optical imaging has been obtained for a complete sample of these objects using the HST ACS showing several of them to have irregular morphologies indicative of an on‐going interaction, supporting the ʺbuilding‐blockʺ interpretation. The GBT will be used to search for neutral hydrogen in the complete sample, and the VLA will follow up with HI images of the detected systems. The GBT spectral line profiles in concert with the total gaseous extent determined from the VLA images will provide strong constraints on the mass scale, dark matter content, and dynamical nature of these smallest galaxies.

One of the fascinating results of the GALEX far‐and near‐UV imaging mission was the detection of UV‐bright regions outside the optical disks of galaxies. For several of these systems, neutral hydrogen images from the VLA were available (many from the HI Rogues Gallery, a collection of peculiar systems images in HI maintained at http://www.nrao.edu/astrores/HIrogues). In these cases, the extra‐disk star forming regions were found to be contained within HI extensions. A sample of other systems from the HI Rogues Gallery has been targeted by GALEX to look for similar sites of extra‐disk star formation. In the coming year, these data will be compared with the HI images and existing optical data to explore if there a correlation between star formation and HI column density in these extra‐disk regions similar to that found within normal disks.

Compact groups provide a unique environment to study the mechanisms by which star formation occurs amid continuous gravitational encounters. These dense groups host a variety of modes of star formation, and they can provide insight into the role of gas in galaxy evolution. Time has been awarded to image a sample of twelve Compact Groups in the Near‐ and Far‐ infrared using the Spitzer IRAC (3.6µm, 4.5µm, 5.8µm, and 8.5µm) and MIPS (24µm, 70µm) imaging detectors. The groups span three stages of a proposed evolutionary sequence: pre‐ interaction, shocked intergroup medium, and smooth intergalactic medium. They include both early‐type dominated and disk‐galaxy dominated groups. The Spitzer data will be compared with archival VLA HI data, to explore the distribution of the cold neutral gas to the sites of star formation and activity identified in the IR images. Of particular interest is whether the dynamical state of the system, as determined from the HI kinematics, is linked to the level of activity, and how the gas content evolves along the evolutionary sequence.

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The Interstellar Medium, Molecular Clouds, Cosmic Masers, Star Formation, and Stellar Evolution

Low‐mass protostars have linked accretion and outflow where magnetic stresses govern the balance between inflow and outflow. A similar understanding of the dynamics associated with early B to late O protostars has not been well‐established. Scientists have obtained time on the Spitzer Space Telescope to observe 8 massive outflow sources to determine the large‐scale outflow boundary, the infrared spectral energy distribution of the driving source(s), and the properties of the surrounding cluster. VLA observations are now in progress to obtain deep, multi‐configuration images of the ionized gas around the selected Spitzer sources to trace flow morphology, energetics and ionization structure to within 100 AU of the protostar where magnetic and/or hydrodynamic collimation processes take place. This data should provide insight to determine if the flows in the Spitzer sample are driven by precessing jets, both jet and wide‐angle wind components; and/or only wide‐angle winds. The detection of inherently well‐ collimated outflows would support the interpretation that massive outflows have similar accretion‐based physical processes to those of low‐mass flows while less collimated flows suggest that there are different processes for high‐ and low‐mass stars.

The discovery of thousands of dense clouds opaque at 8 microns by Midcourse Space Experiment (MSX) and the Spitzer GLIMPSE survey suggests that infrared dark clouds (IRDCs) may represent the earliest observable phases of massive star formation. These clouds exhibit structure on all spatial scales, and observations using the combination of the GBT and VLA will be used to investigate a sample of IRDCs to probe their morphology, physical properties, chemistry, and kinematics. The transitions of the key molecules CCS and ammonia at 23 GHz to be used in this study also have the potential to establish chemical ages for the IRDCs, and will enable direct comparisons with nearby, low‐mass, pre‐protostellar cores.

The VLA will also be used to search for radio continuum emission from Spitzer‐detected star formation cores. These cores, including the first detection in the Lynds dark cloud L1014, were originally thought to be starless, but Spitzer has detected embedded low‐mass YSOs in a handful of these objects. Radio continuum emission has been detected from the stellar core in L1014; the emission is highly polarized and variable which suggests that is likely due to gyro‐ synchrotron emission. The detection of radio continuum emission in other such newly‐found low‐mass objects will help to understand where these objects lie in the process of low‐mass star formation.

It is often assumed that the N2H+ and CCS molecules are unbiased probes of dense pre‐ protostellar cores (PPCs). Recently, systematic differentiation of CO, CS, N2H+, and NH3 toward a sample of 5 starless cores in the Taurus region has been observed. The results of these measurements indicate that the abundances of the CO and CS molecules drop dramatically within the denser (n(H2)>10^5 cm‐3) regions of these cores, while the abundances of N2H+ and

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NH3 remain flat or increase in these regions. Owens Valley Radio Observatory (OVRO), VLA, and Berkeley‐Illinois‐Maryland Array (BIMA) observations of the N2H+, NH3, and CCS emission toward the cold core containing the low luminosity IRAM04191 protostar are not consistent with these conclusions. In the even denser regions of the cores (n(H2)>10^6 cm‐3) high resolution is required to study abundance variations. The observations under study suggest that for densities exceeding n(H2)>10^6 cm‐3, over regions <15 arcseconds in diameter, NH3, N2H+, and CCS become depleted in a similar fashion. This result is important because it suggests that the only molecular probes observable from the ground of the innermost regions may be H2D+ (difficult to observe at 372 GHz) and H3O+ (equally difficult to detect). Molecular probes are thus needed if the kinematics of these inner regions critical to disk/star/outflow interactions are to be determined. The GBT will be used to obtain measurements of the CCS emission toward a sample of preprotostellar and protostellar cores. The intent of this study will be to derive the depletion history of CCS within the early evolutionary sequence of a protostar.

Formaldehyde (H2CO) is a proven tracer of the high density environs of molecular clouds. It is ubiquitous: H2CO is associated with 80% of surveyed HII regions and possesses a large number of observationally accessible transitions from centimeter to far‐infrared wavelengths. Because H2CO is a slightly asymmetric rotor molecule, each rotational energy level is split by this asymmetry into two energy levels. Therefore, the energy levels must be designated by a total angular momentum quantum number, J, the projection of J along the symmetry axis for a limiting prolate symmetric top, K(‐1), and the projection of J along the symmetry axis for a limiting oblate symmetric top, K(+1). This splitting leads to two basic types of transitions: the high frequency delta‐J = 1, delta‐K(‐1) = 0, delta‐K(+1) = ‐1 ʺP‐branchʺ transitions, and the lower frequency delta‐J = 0, delta‐K(‐1) = 0, delta‐K(+1) = ‐1 ʺQ‐branchʺ transitions, popularly known as the ʺK‐doubletʺ transitions. The P‐branch transitions are only observed in emission in regions where n(H2)≥ 105/cm3. The excitation of the K‐doublet transitions, though, is not so simple. For n(H2) ≤ 105/cm3, the lower energy states of the 1(10)‐1(11) through 5(14)‐5(15) K‐ doublet transitions become overpopulated due to a collisional selection effect. This overpopulation cools the J ≤ 5 K‐doublets to excitation temperatures lower than that of the cosmic microwave background, causing them to appear in absorption. For n(H2) ≥ 105.5/cm3 this collisional pump is quenched and the J ≤ 5 K‐doublets are then seen in emission over a wide range of kinetic temperatures and abundances.

The GBT will be used to survey the H2CO 2(11)‐2(12), 3(12)‐3(13), and 4(13)‐4(14) emission toward a sample of star formation regions to exactly identify the high density locations within star formation regions, which will provide gas density measurement which can be used to compare with the physical properties derived from dust emission and infrared measurements of these regions.

Using the submillimeter transitions of H2CO, the Caltech Submillimeter Observatory (CSO) will be used to study the physical conditions in the warm dense cores of molecular clouds. H2CO is

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the ideal molecule for this purpose, since its numerous transitions in the submillimeter allow independent temperature and density determination of the emitting gas. The high excitation transitions in the 650 and 800 GHz windows probably arise from gas which is too warm for depletion to have substantially altered the molecular abundances, and should probe material quite close to the young star(s) buried in the dense core.

Two of the more direct observables which constrain protostellar evolutionary theories are the spectral energy distribution (SED) and the spatial intensity distribution of dust continuum emission. Until recently the main tool for determining the evolutionary state of a protostellar core has been measurements of the SED. Unfortunately, the relationship between the SED and the distribution of matter in a protostellar core is not unique. A powerful tool for constraining the distribution of matter in a protostellar core is the measurement of the spatial intensity of long‐wavelength (optically‐thin) dust continuum emission. During the last decade instrumentation, such as the Submillimeter Common User Bolometer Array (SCUBA) have been developed which greatly enhance the ability to make measurements of the spatial distribution of matter in protostellar cores over spatial scales (1,000 – 10,000 AU) which can be used to constrain evolutionary theories.

High spatial resolution measurements of the centimeter‐wavelength dust continuum emission are key to these evolutionary characterizations, as long‐wavelength dust continuum emission has the highest probability of being optically‐thin, and therefore a direct measure of the mass in a protostellar core. When combined with dust continuum observations at submillimeter wavelengths, millimeter continuum observations provide a substantial lever‐arm to constrain dust opacities. The GBT is the most sensitive telescope at long‐millimeter wavelengths, and will be used to image protostellar cores at 7mm and 9mm.

Using the VLA, OVRO, CSO and the GBT a program to investigate chemical change in preprotostellar cores has begun. Observations of molecular distributions will be contrasted with existing observations of the distribution of dust and with models derived from those observations to investigate the role of molecular depletion. Observations of ammonia (VLA) and the related N2H+ molecule (OVRO, Five College Radio Astronomy Observatory) in one core forming a very low mass star have revealed that both molecules are depleted by orders of magnitude in regions where the density exceeds about 1.5 x 106/cm3. Depletion is so complete that no known molecule can be used to trace the core kinematics, with the possible exception of the exceedingly difficult to detect H2D+ molecule. Is depletion a feature of preprotostellar cores on the verge of star formation? The aforementioned survey of the densest cores from a recent compendium has commenced to answer this question.

In warmer cores, depletion may not play a significant role in cloud evolution. To study this, a complete sample of young massive star forming regions imaged in dust and the lines of HCO+ J=3‐2; N2H+ J=1‐0 and J=3‐2 will be compared to determine if depletion plays any role in their

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chemistry. If CO becomes depleted, HCO+ will follow and N2H+ will strengthen; if depletion is unimportant, N2H+ will remain a minor species.

The densest warmest parts of these massive star forming regions may harbor ʹhot coresʹ, of which the Orion hot core is the closest example, though not the most massive. Complex molecules are found in these regions; recent searches have focused on the Orion core and one of the cores in Sgr B2, for glycine transitions and for those of related prebiotic species, adenine, and uracil, which have transitions in this frequency range. Even in the densest hot cores, the GBT will find only modest dust opacity. However, at the ALMA or Herschel frequencies this may not be the case. In the extreme example of a massive hot core, high dust opacity might completely shield the coreʹs molecular composition from view at the highest frequencies.

Formaldehyde has several ladders of transitions, including the well‐known Delta‐J=0 set at centimeter wavelengths. These transitions will be investigated with the GBT and compared to transitions arising from the same levels at Terahertz frequencies, observing with the CSO, to assess the importance of this effect.

The youngest stars have not yet heated their birthplace, nor have they even accreted most of their mass from it; they inhabit the coldest of molecular cloud cores. Within these cores, the spectral energy distribution has yet to be shaped by the star; it peaks in the submillimeter with a characteristic temperature of only tens of degrees Kelvin. Cores showing these so‐called ʹClass 0ʹ energy distributions (SEDs) have been targeted for ammonia imaging with the VLA; maps of another half dozen are scheduled for observation late this summer. Apparently simple cores, characterized by cold dust and bipolar flows, have been targeted to determine the rotational properties of the cores in these early stages. Presumably, as material has not yet settled into a circumstellar disk, the angular momentum of the parent cloud may be measured through the ammonia images and contrasted to properties of the bipolar flow. An earlier survey which presented VLA observations of linear gradients in the single‐protostellar objects HH211, HH212 and HH111, has been extended to measure gradients in other cores, including NGC2023‐mms, HH24‐25 cores, L1634 and IRAM04191; a link will be demonstrated between source age, outflow momentum and outflow character in this enlarged set of sources. This further set includes multiple objects; the goal is to determine how formation of multiple objects alters the angular momentum and energy budget between circumstellar gas, embedded sources and outflowing jets.

A program has imaged these same cores in the lines of formaldehyde at 1.3mm, using the BIMA interferometer. These lines lie at nearly exactly the same energy as the ammonia lines; any difference in the images should stem primarily from chemical differences. The goal here is to develop millimeter wavelength probes of temperature and density analogous to ammonia for the higher frequency ranges to be imaged by ALMA.

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GBT and VLA observations of ammonia will be combined to provide complete flux maps in several low mass dense cores to investigate on smaller scales the structure of temperature and density deduced on larger (0.05 pc) scales from total power images.

Another excellent probe of cold near‐protostellar material is provided by deterium isotopomers of abundant molecules. Several cores in the Serpens cloud and in NGC1333 have been mapped at BIMA so far in a number of isotopomers. The effects of grain chemistry in the envelope have been separated by contrasting emission from deuteroammonia, which may form on grains and be released by energetic events near the protostar, with the deuterated formyl ion, which does not participate in grain chemistry.

The only available probe of the inner AU or so of a protostar remains water maser emission. A program of mapping masers over time to determine true space motion of the flow continues, using the VLA, the VLBA and the Pie Town link. Mser proper motions in regions forming more massive stars will also be investigated. Generally, the maser components are more numerous and appear to evolve more quickly in these regions. In one region of note, a complex maser system produces masers over a fairly broad velocity range in a complex pattern. However, a nearby maser at extremely high velocities has appeared regularly which apparently is unassociated with the main complex and its millimeter continuum core.

Several coordinated projects studying the atmospheres and mass losing regions of Mira stars using the VLBA and IR interferometers will continue. SiO masers, which can be studied using the VLBA, arise between the outer parts of the molecular envelopes, studied by near IR interferometers and the dust forming regions, studied by mid‐IR interferometers. These coordinated observations can help in the understanding of the mass loss mechanisms in these evolved stars which are one of the major contributors to the interstellar medium and which are currently poorly understood.

A review of molecular outflows from massive young stellar objects (early B and O spectral types) shows that there are both well‐collimated and poorly‐collimated molecular flows from massive stars. To account for the differences seen in flow morphologies from early B to late O stars scientists at NRAO and the CfA proposed a new evolutionary sequence to explain the observable outflow signatures. The sequence proposes that massive flows begin collimated and become less‐collimated as the star reaches the Zero Age Main Sequence and generates significantly more Lyman continuum photons. Evidence for this scenario comes from VLA observations of ionized outflow gas along with millimeter interferometer observations of the larger scale flows. Well‐collimated molecular flows tend to be in younger systems where the central object has not yet reached the main sequence. Hence the effects of increased irradiation on the disk and disk‐wind due to the stellar radiation field are minimized. Observed jets often have opening angles between 25 and 30 degrees with little evidence for re‐collimation of the jets on larger scales. This could be due to a change in the balance between magnetic and plasma

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pressure. Poorly collimated flows are associated with more evolved sources that have detectable UC HII regions and the central star has reached the main sequence. Thus, the disk and outflow are subject to significantly more ionizing radiation. This evolutionary sequence appears to qualitatively fit the observations; however, this proposal must be tested against both theory and observations.

Observations were made of the massive star forming region associated with the early B protostar G192.16 ‐ 3.84 in ammonia, water masers, 1.3 cm continuum emission, and at 850 microns. The dense gas associated with the massive protostar is clumpy, optically thin, and has a mass of 0.9 M(sun). The ammonia core is gravitationally unstable which may signal that the outflow phase of this system is coming to an end. Water masers trace an ionized jet 1600 AU north of G192.16. Masers are also located within 500 AU of the massive protostar; their velocity distribution is consistent with but does not strongly support the interpretation that the maser emission arises in a 1000 AU rotating disk centered on G192.16. Roughly 0.3 pc south of G192.16 is a compact, optically thick ammonia core (G192 S3) with an estimated mass of 2.6 Msun. Based on the presence of 850mµ and 1.2 mm continuum emission, G192 S3 probably harbors a very young, low‐mass protostar or proto‐cluster. The dense gas in the G192 S3 core is likely to be gravitationally bound and may represent the next site of star formation in this region.

The VLA will be used to continue to survey the environment of HII regions for water masers associated with low‐mass young stellar objects (YSOs). The Sun was likely born in this kind of environment, not in a molecular cloud which only produces low‐mass stars, like Taurus, or Ophiuchus. Thus it is important to understand the evolution of young, low‐mass stars in the near‐HII region environment (such as Orion or M16) to understand the formation of the Sun and our planetary system. Weak and variable water masers are found near low‐mass YSOs, and are good tracers of low‐mass star formation. Once found, these water masers can be observed with the VLBA to study in detail the near‐stellar environment of low‐mass stars in HII region environments and compare to what is already known about more isolated cases of star formation.

The GBT will be used to study the molecular environments of planetary nebulae (PNe). Although the central stars of PNe are very hot a significant fraction of PNe are surrounded by massive, molecular envelopes with highly fragmented structures. The high spatial resolution and sensitivity of the GBT provides an excellent match to these objects. These data, when combined with numerical models, will probe the physical and chemical environments of PNe and constrain stellar evolution mixing theories.

The VLBA will be used in the upcoming year to measure the absolute positions of water masers in the nearby low‐mass star‐forming region, Rho Ophiuchus. Repeated measurements (twice per month) of the absolute maser positions will enable NRAO scientists to disentangle the

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parallax, the overall cloud motion, and the peculiar water maser motions. The parallax measurement will allow an estimate of the distance to the water masers with an accuracy of about 0.5 %. Not only will a precise distance lead to the best determination of the luminosities, jet velocities, outflow momenta, and many other physical quantities of this star‐forming region, but it will also provide a unique opportunity to investigate the three‐dimensional structure of the cloud and its relationship to the stars in the Upper Scorpius subgroup. Different water maser sources associated with different parts of the Rho Ophiuchus cloud will allow a relative distance determination of YSOs along the line of sight. The VLBA is the only instrument in the world that has the capability to make this kind of accurate measurement.

The VLBA will also be used to continue to refine techniques in accurate absolute position measurements at high frequencies (especially at 1.3 cm using the water maser line) to extend such measurements reported in the last paragraph to star‐forming regions across the Galaxy. In addition, water maser sources around Mira and AGB stars can also be used to measure parallaxes and the peculiar motions will allow the simultaneous study of the gas dynamics in the circumstellar envelopes of these late‐type stars.

The VLBA will be used to track OH maser motions in massive star‐forming regions. Preliminary reduction of the data from a few sources suggests that slow expansion, as observed in sources such as W3(OH), is the dominant kinematic mode of interstellar OH masers. However, outflows may determine the motions in some sources, such as W75 N VLA 2. The data may also help determine whether sources without a detectable H II region are young enough to still be accreting material.

A proposal has been submitted to survey 110 square degrees of the northern Galactic plane covered by the GLIMPSE Legacy program and a deep near‐IR survey by the UK IR Deep Sky Survey consortium using the VLA at 6 cm wavelength in the B configuration. These data should help distinguish between radio‐loud ultra‐compact HII regions and radio‐quiet massive young stellar objects. Results of this survey will be released as they become available.

The GBT will be used to make observations of HI emission from high‐velocity hydrogen clouds for correlation with new infrared observations, in a search for dust in these objects. In the galactic disk the amount of far‐infrared emission is directly related to the total amount of gas, arising from the tight coupling of gas and the warm dust which produces the IR emission. But no IR emission has even been detected from a high‐velocity cloud either because they have low metal abundances or are very cool. With new IR data from Spitzer and the high‐quality HI measurements from the GBT we expect to detect the signature of dust from the high‐velocity clouds and measure its properties.

The GBT will be used to make a precise map of Galactic HI emission over a large area at high latitude to determine the galactic foreground which will affect analysis of the Planck Microwave

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Background experiment. This work will be done in conjunction with HI observations at the Dominion Radio Astrophysical Observatory (DRAO). The DRAO interferometer will supply HI spectra at 1ʹ arcminute angular resolution, while the GBT will supply the short‐spacings and higher sensitivity spectra. The next generation of Cosmic Microwave Background Radiation experiments require knowledge of galactic foregrounds to eliminate confusion and contamination, and this project will be a first step in these efforts.

The WSRT will be used to obtain deep, high resolution Galactic HI 21cm absorption/emission spectra towards a sample of fourteen bright, high‐latitude radio sources. This will test whether a new population of tiny discrete features in the diffuse interstellar medium, presently detected with the WSRT towards four sources, is indeed ubiquitous. Substantial injection of small‐scale power into the ISM would be needed if such structures are very common, posing problems for theoretical models. These observations will also obtain the power spectrum of galactic HI, at very low HI column densities.

The GBT will be used to measure HI absorption towards pulsars to: (a) improve distance estimates to the pulsars; (b) search for anomalous velocity HI clouds in the ISM; (c) improve models of electron density in the ISM through refined pulsar distances, and (d) to search for small scale variation in the HI absorption towards the pulsars.

The GBT will be used to study small scale structure in the ISM which results in specific scintillation patterns in pulsar dynamic spectra and its Fourier conjugate, the secondary spectrum. Arclets observed in the secondary spectrum provide information on the location of the scattering material along the line of site; these effects may well be related to extreme scattering events.

The structure of the ISMʹs magnetic field on ~ 109 m scales will be probed through investigations of anisotropy of interstellar turbulence. Scintillation studies of some pulsars and certain compact extragalactic sources reveal that these sources are often scattered by thin layers of turbulence. This turbulence is sometimes found to be highly anisotropic, particularly in the scattering screens associated with intra‐day variable quasars.

The nature of interstellar turbulence will also be studied through VLBI measurements of pulsar scattering disks. Analysis of pulsar secondary spectra‐power spectra of the scintillations spectrum in time and frequency‐reveal the presence of unusual scattering structures which appear to be distinct from the Kolmogorov‐like turbulence usually observed in interstellar scattering. These objects appear to be discrete structures with high inferred particle densities 104/cm3. Secondary spectra, when combined with VLBI astrometric techniques, can be used to construct a complete picture of the scattering conditions and clarify the nature of these discrete objects.

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X‐ray absorption measurements along the line of sight to the galaxy cluster Abell 478 show an unexpectedly large column density of hydrogen in comparison to the value inferred from Galactic 21cm emission surveys. One possibility is that the Galactic values are in error due to high optical depth or a misestimated spin temperature. The VLA will be used to probe 21cm absorption in this direction as well as the GBT to create a higher‐resolution Galactic emission image.

To look for the Zeeman Effect in absorption, 6.0 GHz OH absorption data from Effelsberg will be analyzed. Comparison of the magnetic field strengths obtained from OH absorption and maser emission will allow comparison of the magnetic field strengths in and outside of OH maser sites. Since the magnetic field strength can be used as a proxy for the density, this may help determine whether OH masers are denser than the surrounding medium. If so, this would suggest that OH masers are physical entities rather than merely chance alignments of velocity‐ coherent material in an otherwise homogeneous medium.

A tentative detection of interstellar OD will be further investigated. If the detection is real, this is the first time that OD has been observed in interstellar space. The abundance relative to OH appears to be much higher than the D/H abundance ratio, suggesting significant chemical enhancement. Deuterium fractionation has been seen in other molecules and is predicted in OD, though to a lesser extent than observed. High‐resolution, high signal‐to‐noise observations of this region with the WSRT will allow for an accurate measurement of the OD/OH abundance ratio, which in turn will allow investigation of whether current models of molecular deuteration are reasonable.

The GMRT will be used to image 1065 MHz acetaldehyde and 1372 MHz vinyl cyanide line emission from a sample of Galactic molecular cloud complexes, to test whether organic molecules are confined to hot cloud cores or are widespread in the Galaxy. The observations will determine the large‐scale kinematics and spatial structure of organic molecules in these molecular clouds and will test whether grain mantle destruction by shocks plays an important role in the observed gas phase abundance of these species.

The GBT will be used to search for the 1_{10} to 1_{11} hyperfine transitions of the simplest amino acid, glycine, at ~ 963 MHz, towards SgrB2. The detection of glycine would be of considerable importance since it is a key bio‐marker that would provide crucial evidence for extra‐terrestrial pre‐biotic evolution. Previous searches for glycine (all non‐detections) have concentrated on its high frequency transitions, which are favored at high rotational temperatures (> 100 K). While such temperatures are typical of molecules in compact hot cores, it is possible that glycine is spatially extended and, like glycolaldehyde, has a low rotational temperature; this molecule might then not be detectable at mm‐wavelengths but could be detected in the 963 MHz hyperfine transition.

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The Galactic Center, Pulsars, Novae, Supernovae, X‐ray Binaries, and other Radio Stars

The excellent pulsar capabilities of the GBT are enabling the most sensitive pulsar survey of the Northern galactic plane. The survey should produce many dozens of new pulsars, including one or more very rare millisecond pulsars (MSPs). The discovery of even a single new ʺwell‐ timingʺ northern MSP may be essential to the success of pulsar timing arrays for discovering extremely low‐frequency gravitational waves.

With low‐interference and high‐bandwidth capabilities of the S‐band receiver / Spigot backend combination, work will continue on timing the bonanza of at least 34 new MSPs found this past year in several globular clusters located in the Galactic plane. Since many of the new exciting results from pulsars originate from timing observations, this fascinating zoo of new exotic systems will provide many likely surprises. Possibilities include tests of gravitational theories and constraints on the equation of state of matter at supra‐nuclear density.

In addition to the searches and timing observations, the GBT will continue to push the state of the art in non‐traditional pulsar observations like scintillation observations and HI absorption measurements, providing key probes into the structure and make‐up of the interstellar medium.

The orthogonal modes of polarization (OPM) in pulsar radio emission are thought to arise from propagation effects in the pulsarʹs magnetospheric plasma. However, the origin of OPM remains uncertain, primarily because observations of mode polarization have been restricted to a narrow frequency range. Multi‐frequency, single‐pulse polarization observations of nearby pulsars will be made with the Arecibo radio telescope in an effort to determine the origin of OPM and to investigate how the emission depolarizes at high frequency.

The GBT will be used at 2 GHz to study mysterious giant pulses from the millisecond pulsar B1937+21 with temporal resolution of about 15 ns. The large collecting area of the GBT will provide sufficient sensitivity to study the high‐energy giant pulses and their energy volume density, search for a possible low‐energy trigger limit, and investigate polarization properties of the giant pulses. This project will provide constraints on the physics of the pulsar radio emission.

The double pulsar J0737‐3039 is one of the most extraordinary systems in all of astronomy. NRAO telescopes have been part of a multi‐wavelength collaboration working to determine the properties of this system. Observations at the VLA have determined the flux density and spectral index of the double pulsar, as well as its orbital modulation. Over the next year, NRAO astronomers will conduct X‐ray observations of the source in collaboration with astronomers at the Center for Astrophysics, as well as continuing to observe it at radio wavelengths. These

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observations constrain theoretical models of the interaction between the relativistic winds of the two pulsars, and are expected to provide insights into the long‐standing problem of how a neutron starʹs electromagnetic flux is converted to kinetic energy in a particle outflow.

The GBT will be used in conjunction with Arecibo and two large European radio telescopes to observe scintillation arc phenomena in pulsars using a new observing method. Scintillation arcs can be related to the distribution of power in a pulsarʹs secondary spectrum that are interpreted as multiple slit interference patterns produced by a moving screen. A VLBI‐like technique will be used to image the two dimensional distribution of these slits, allowing measurements of scattering anisotropy and ISM fluctuation power spectra on extremely small scales (0.01 to 0.1 mas).

The nature of pulsar emission mechanisms will be probed by investigating the higher‐order statistics of the radiation field. Ultra‐high time resolution baseband recorders make it possible to probe the statistics of the radiation on time scales close to the temporal coherence scale. The characteristics of the radiation, when investigated on these short time scales, is expected to contain information about the mechanism that generates the radiation. For instance, this technique has already proven useful in confirming the nature the ~40 MHz emission from the Jupiter‐Io system (Jovian decametric S bursts).

The nature of the millimeter‐ and centimeter‐wavelength variability of SgrA* will be investigated using VLA, ATCA and Combined Array for Research in Millimeter‐wave Astronomy (CARMA) observations. Of particular interest is the issue of short‐timescale variability at millimeter wavelengths and the possible connection to IR and X‐ray flares. A connection is suspected, but it is unknown whether the X‐ray flares precede radio flares or vice‐ versa, and thus if the X‐ray flares are caused by up‐scattered radio photons. The contribution interstellar scintillation might make to the variability on inter‐day time scales at mm wavelengths will also be investigated.

In preparation for new 43 GHz VLBI observations in the Galactic center, in particular with the Japanese VLBI Exploration of Radio Astronomy (VERA) array, the VLA will be used to monitor relatively strong 43 GHz SiO masers within two degrees of Sgr A*, the nuclear black hole. This bi‐monthly monitoring will result in 43GHz line light‐curves and will likely lead to selection of suitable phase calibrators to observe Sgr A* and any other high‐frequency source (such as the many AGB stars) in the Galactic center at any time. This process will enable astrometry of these sources and yield the gravitational potential and mass distribution of the inner tens of parsecs of the Galaxy.

GBT polarization measurements at centimeter wavelengths will be used to calculate the distribution of rotation measure, magnetic field, and spectral distribution across the Galactic Center Lobe (GCL). The goal will be to determine: (a) if all the features of the GCL are part of a

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single coherent structure, (b) the nature of the emission mechanism (thermal, non‐thermal); (c) relationship of the lobe with the immediate environment, and (d) the energetics and origin of the GCL.

The VLBA and the VLA will be used to observe black hole candidate V404 Cyg to test the standard model that the radio emission from the source arises from a small jet and whether small flaring episodes are ejection events. The VLBA will also be used to observe SS433 over a period of 2 weeks coincident with optical and X‐ray (Chandra) spectroscopy. This will show whether the discrete Doppler shifted lines seen in the optical and X‐ray correspond to the emergence of components in the radio jet of SS433.

Ultraluminous X‐ray sources (ULX) are enigmatic objects whose X‐ray emission exceeds the Eddington limit for accretion onto stellar mass compact objects. A continuing study of VLA archival data will reveal the radio properties of these objects, which can be used to determine whether ULXs are beamed sub‐Eddington sources of normal stellar mass compact objects or are more exotic intermediate mass black holes emitting isotropically at sub‐Eddington luminosities.

X‐ray observations with the Rossi X‐Ray Timing Explorer (RXTE), combined with radio data from the VLA and VLBA, will be used to further explore the connections between accretion and relativistic ejection in X‐ray binaries. Conditions in the inner accretion flow around collapsed objects (neutron stars and black holes) reveal unexpectedly rich evolution on timescales of milliseconds to months. The accretion originates from a binary companion. Accretion disk X‐ ray spectra, spectral hardness, and power‐law indeces, indicate systematic changes in the accretion properties as a function of the AU‐scale jet emission imaged by the VLBA. The relationship of X‐ray intensity fluctuations measured by RXTE (the so‐called timing properties) to the radio jet will be further explored by observing the changes surrounding major radio/X‐ ray flare events. A VLA monitoring project will continue to provide crucial radio data on X‐ray transients, and supply suitable candidates for imaging and astrometry using the VLBA. Recent surprises from the VLA monitoring campaigns include emission from long‐lived ejecta years after the initial flare, displaced by arc seconds from the central object; radio emission with shell morphology (i.e., spherical shocks) rather than in jets, and radio emission at unexpected times, and intensities from accreting millisecond pulsars. A program using Chandra and the VLA will observe black hole transients as they return to quiescence. The study of the radio/X‐ray relation as a function of mass accretion rate, covering six or more orders of magnitude in X‐ray luminosity, constrains the models of accretion flow (e.g.Advection Dominated Accretion Flows) and their connection to jet production. VLBA astrometry of X‐ray binaries will measure their space velocities and Galactocentric orbits based on VLBA proper motion and optical radial velocity. Parallax measurements may well be possible in some cases. The velocities can provide information about possible kick velocities of black holes (and similarities to pulsar birth events) and birth locations of black hole binaries.

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The GBT will be used to carry out low‐frequency observations of Galactic supernova remnants in conjugation with the VLA/GMRT. In particular, the energetics, dynamics and interaction of the supernova remnants with the ISM will be studied using spatially resolved low‐frequency continuum spectral index changes combined with spectral line observations.

The VLA will be used to search for intermediate black holes in globular clusters. The VLA archive has been searched for data on the globular clusters most likely to have black holes at their centers, based on theoretical calculations, with negative results. The planned observations will go deeper and at a higher frequency to avoid pulsars.

The Solar System and other Planetary Systems

Passive radio observations of solar system objects allow properties of their atmospheres, surfaces, and magnetic fields to be inferred. Active radio observations (radar) allow additional properties of surfaces and magnetic fields to be inferred, and can also give insights into the spin state of the probed body. Radio wavelengths are unique in their ability to probe into regions inaccessible to shorter wavelengths, e.g., into the deep atmospheres and into the subsurfaces of planets. They are also unique in their ability to observe in conditions which would make shorter wavelength observations useless (daylight, cloud cover, etc...). They have therefore made, and continue to make, important contributions to planetary astronomy and science.

Radar observations of Mars provide important constraints on the surface and subsurface properties, including structure (or ʺtextureʺ). The combination of the Goldstone transmitter and the VLA provides a powerful direct‐mapping bistatic radar instrument which has been used successfully during the oppositions of 1988, 1992/93, and 1999 to make radar reflectivity maps of the planet. The opposition of 2003 was a fantastic opportunity to continue the successful Goldstone/VLA experiments in this respect. Questions regarding the differences between the south and north ice caps, ʺStealthʺ regions, the Hellas basin, and other interesting areas on the planet can be addressed with data taken during this opposition. That data is being reduced currently, and will be presented at the DPS meeting in 2006. Preliminary results are that the south polar ice cap is quite reflective, including the seasonal cap. This is the first time that an increase in reflectivity from a seasonal cap has been seen, and can be used to infer that the seasonal cap is thick (≥~ 1 meter) and jumbled. The 2003 Mars opposition also provided an excellent opportunity to once again observe the tenuous water vapor in its atmosphere with the VLA. These data will constrain the amount and vertical distribution of water vapor in the atmosphere of Mars as a function of time.

Radio observations of Uranus provide important information on the deep atmosphere, including temperature and abundance (notably of ammonia, the major variable contributor to opacity at these longer wavelengths). Observations during the next few years will be especially important, as the planet is nearly at equinox. In 2007, its north pole will emerge into sunlight

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for the first time in 42 years. Observations of the deep atmosphere are critical in deducing the dynamics of the deep (and shallow) atmosphere. A program of VLA observations of the planet during every A‐configuration will continue, including comparing new results to the very recent results indicating that high northern latitudes are bright, just like the high southern latitudes, and that mid‐latitude banding is apparent at high frequencies (K‐ and Q‐bands). Additionally, new longer wavelength observations will be compared to recent data which indicate that the south pole brightening persists to great depths (≥~ 50 bars).

With the Cassini spacecraft in the Saturn system, observations of that planet and its moons are especially important during the next few years. In particular, its largest moon Titan is one of the more enigmatic bodies in the solar system. VLA observations of Titan were taken during the last opposition in the VLA A‐configuration, which will be used to constrain the atmospheric and surface properties of this large icy satellite of Saturn.

Astrometry

The International Celestial Reference Frame (ICRF), the fundamental celestial grid for all astrometric work in astronomy, is defined by the accurate radio positions of 600 extragalactic radio sources at 8.4GHz. These positions have been determined from VLBI observations over more than 30 years. Since Goddard Space Flight Center (GSFC), the U.S. Naval Observatory (USNO) and NRAO have included the VLBA in the observations over the last ten years (after the ICRF was established in 1995), the grid accuracy has significantly improved, and six 24‐hour VLBA runs in 2006 will continue to improve the astrometric quality of the ICRF. A revised ICRF list to be defined by the IAU should be available after the next IAU General Assembly in 2006.

Approximately 3000 additional radio sources have been observed with the VLBA to determine the quality of these sources as potential ICRF candidates, to tie their positions to the existing ICRF grid, and to produce a VLBA catalog of phase‐referencing calibrator sources. Additional VLBA observations in 2006 will be used to find needed calibrator sources near the galactic plane and south of ‐20 deg declination.

A group from the Jet Propulsion Laboratory (JPL), USNO, GSFC and NRAO have used the VLBA at 23 GHz and 43GHz in order to define the ICRF at a higher frequency than 8.4GHz, where source structure and the ionosphere turbulence are less of a contaminant to accurate positions. These VLBA observations will continue in 2006. A major impetus for establishing this ICRF grid was the possibility of using the VLBA for spacecraft navigation at 33 GHz, including the Mars missions in 2007. The operational, instrumental and reduction techniques for navigation were established with VLBA observations in 2005. However, the lack of NASA support for spacecraft navigation means that little or no observation of this type will be done in 2006.

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About 30% of the total VLBA observing in 2006 will be used for astrometric‐type observations: determining the proper motion, parallax, orbital and secular motions of pulsars, X‐ray binaries, peculiar stars, masers emission in the atmosphere of giant stars, and tests of general relativity. The typical astrometric precision for radio sources stronger than 1 mJy at 8 GHz is about 100 microarcsec per observing epoch, an order of magnitude better than from any other astronomical technique, and accuracies to 10 microarcsec have been obtained. VLBI astrometric observations are much more common than even five years ago because of the VLBA instrumental stability, the positional accuracy of the ICRF, the high density of VLBA calibrators, and the improvement in the astrometric reduction packages.

The radio source 3C279 will be observed as the line‐of‐sight passes closest to the sun. VLBA observations will directly measure the deflection of the 3C279 radio emission by the solar gravitational field. We will accurately measure the position of 3C279 with respect to a series of reference quasars by using the radio‐phase referencing technique. Our observations will be conducted using the VLBA and VLA at U, K and Q‐bands. These new observations will enable the determination of the relativistic gamma term to a factor of 10 to 100 times more accurate than previously measured using VLBI. While the Cassini spacecraft passed behind the sun on its journey to Saturn, additional delay was measured in the spacecraftʹs downlink signal. The NASA‐JPL group measured the solar gravitational gamma to nearly one part in 100,000. The new VLBA observations will be able to independently achieve a result of the same accuracy.

A recently‐concluded large VLBA project has measured the parallax of over 20 pulsars through sub‐milliarcsecond astrometry at eight epochs spread over two years. As the feasibility of the astrometry techniques has been demonstrated, a VLA precursor survey has been undertaken on a more challenging sample of objects. Over the next year, another large VLBA project will begin to observe the new sample. Accurate astrometry provides model‐independent distances and velocities for pulsars, which will be used in aggregate to investigate the neutron star population velocity, the distribution of Galactic electron density, and the core collapse processes in supernovae. Individual measurements will also reveal birth sites, confirm (or refute) supernova associations, and provide true ages, as well as providing important solar‐extragalactic reference frame ties.

Astrometry of three young stellar objects in the T Tauri Association using the VLBA will be completed. An additional 2 stars in T Tauri and 5 stars in Rho Ophiuchus have been added to the project and observations with the VLBA will proceed over the next year. The goals of this project are to obtain a highly accurate (< 2% error) distance, measure additional acceleration terms due to the gravitational interactions of these stellar systems, and start to understand their spatial distribution.

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Instrumentation

Research and development continues on antenna arrays with applications to both aperture and focal plane arrays. A new circuit model for mutual coupling, developed at NRAO, will be refined and tested with antenna simulation software and with measurements on the Green Bank antenna test range. Understanding of mutual coupling is crucial to optimizing the performance of low‐noise, close‐packed arrays. Other array issues, such as reverse amplifier noise, required digitization fidelity, small‐scale cryogenics, and signal processing architectures will also be studied.

Effective pulse blanking algorithms have been developed and proven for the excision of aircraft navigation signals from radio astronomy data in the 960‐1400 MHz range of great interest to studies of highly redshifted radiation of neutral hydrogen (HI) and the hydroxyl molecule (OH). Engineering is now underway to implement these algorithms in real‐time hardware for routine use by astronomers at the GBT and other telescopes. RFI mitigation research will now be directed toward adaptive and feed array cancellation of signals from TV and cell phone transmitters in the 300‐960 MHz range. The cancellation techniques have proven effective on satellite signals, and the new research will investigate the added complication of multi‐path propagation of signals from terrestrial transmitters.

The Penn Array Receiver (PAR), a 64‐pixel bolometer array operating in the 86 to 94 GHz range, will be tested on the GBT in early 2006. The PAR receiver uses Transition Edge Superconducting (TES) bolometers and closed‐cycle cryogenics. These technologies are suitable for possible large bolometer arrays in the future. Continuum imaging algorithms for the PAR are also being tested and implemented. The PAR will be available as a user instrument at a later date. The PAR will eventually enable the best long mm‐wavelength measurements of dusty galaxies to be made, constraining dust models for these systems. The Penn Array will also have excellent sensitivity to very highly redshifted dust emission.

Work will begin on the Zpectrometer, an ultra‐wide bandwidth spectrometer for the GBT at the University of Maryland. This instrument will cover the full 14 GHz‐wide Ka‐band with a set of analog lag correlation spectrometers in a multi‐channel correlation radiometer architecture. Its bandwidth and stability, combined with the GBTʹs collecting area, will enable sensitive and efficient spectral searches for molecules in high redshift galaxies. The instrument will be optimized for observations of low‐excitation spectral lines from the carbon monoxide (CO) molecule at redshifts of 1.88 < z < 3.43 and 4.76 < z < 7.87. This range of redshifts is of intense current interest because it may correspond to the era when most of the stars in the Universe formed and galaxies assembled.

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Software development will continue for the Zpectrometer. This effort will include the development of novel algorithms for the detection of weak molecular lines in wide‐bandwidth data.

A new 26 ‐ 40 GHz receiver has been commissioned on the GBT, and final commissioning (transitioning to production astronomical use) will occur in 2006. In addition a fast‐switching continuum backend, the Caltech Continuum Backend CCB, is under construction in the lab and will be commissioned in winter 2005/2006. This backend will simultaneously detect power from both polarizations of both feeds over the entire receiver band. Both the new 26 ‐ 40 GHz receiver and the CCB will be available as user instruments. The Ka‐band receiver, in conjunction with the CCB and the GBTʹs present 30 GHz aperture efficiency, will be the worldʹs pre‐eminent cm‐wave continuum capability for discrete source measurements.

NRAO engineers are continuing the development of Monolithic Millimeter‐Wave Integrated Circuits (MMICs) and MMIC‐based subsystems for the current and next generation of centimeter and millimeter‐wave radio astronomy receivers and arrays. For example, custom MMIC power amplifiers, multipliers, and mixers are key components in the ALMA local oscillator (LO) system. MMICs provide highly repeatable performance in a more compact package than traditional millimeter‐wave assemblies, and at lower cost in large quantities. This dramatically improves the tradeoff between cost and performance in array architectures.

As the cost of GaAs and InP wafer runs is quite high, it is most efficient to share mask sets with collaborators whenever possible. There will be several opportunities to do so this year. While these wafer runs are necessary to complete receiver components for existing projects such as ALMA and the EVLA, they also provide the opportunity to prototype new experimental designs for future upgrades and applications. Other potential MMIC research areas will include decade‐bandwidth components, the integration of low‐noise amplifiers with antenna structures, and large‐dynamic range module designs for future arrays such as FASR.

The development of new‐generation submillimeter‐wave mixer‐circuit technology will continue in the next year. In particular, the joint R&D project (between NRAO CDL and the University of Virginia Microfabrication Laboratory) to develop the beam‐lead quartz chip technology for superconducting millimeter‐wave circuits (385 to 500 GHz) will proceed in 2006. Two new designs, one that uses the microstrip self inductance of the array as the main tuning element and another that uses a new two‐junction tuning design, have been developed for the 385‐500 GHz SIS mixer using UVA’s new 3 micron‐thick Silicon on Insulator (SOI) wafer technology. The goal of this development effort is to demonstrate the feasibility of using SOI technology in fabricating submillimeter wave circuits. The new mixer design, if successful, can also be used as the prototype design for future THz mixers.

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The GBT pulsar Spigot will be improved to provide new modes that continue to utilize its state‐ of‐the‐art wide bandwidth (800MHz) capability but yet feature higher frequency resolution, better dynamic range, improved ease‐of‐use, and the ability to ʺfoldʺ pulsar data in real time. In addition, full Stokes polarization capability may prove to be possible.

The upgrade of the VLBAʹs original tape recording system to Mark 5 disk‐based units will continue. The initial phase, approximately half complete as of October 1, 2005, is being carried out while maintaining the VLBAʹs historical 128‐Mbps mean recording rate. Additional efforts in 2006 will concentrate on improving the flexibility and reliability of the Mark 5 system, and its interoperability with other VLBI facilities. Most benefits from this phase will be operational in nature: more flexible use of the recording media, reliable reproduction of recorded data, instantaneous synchronization in the correlator, and a major reduction in the cost of maintaining the recording system. Scientific benefits, primarily a root‐8 increase in continuum sensitivity, will follow as the sustainable recording bandwidth is increased to 1 Gbps through subsequent expansion of the media pool.

Continued development of low‐frequency (74 MHz) interferometric calibration and imaging techniques are anticipated. These techniques are needed for optimizing the scientific results from the current VLA 74 MHz system and are critical for the Low‐frequency Array (LWA) now being considered in the U.S. Southwest.

Algorithm Development

New imaging techniques for the processing of high‐precision full‐beam and multi‐field mosaic data in full polarization will be developed, e.g., for use with ALMA, EVLA, GBT, and other community instruments.

New imaging and deconvolution techniques to deal with ultra‐wide band and ultra‐wide field interferometer data will be developed, relevant for next generation arrays such as EVLA, Allen Telescope Array (ATA), LWA, Low Frequency Radio Array, and the Miluera Widefield Array.

Observations with the current VLA and VLBA are being used to study polarization calibration techniques which will be important for the EVLA and ALMA. Work so far has indicated that the instrumental polarization of the VLA, while substantially variable in frequency, is exceptionally stable on timescales of months to years, especially at low frequencies. Even for total intensity imaging programs not concerned with polarimetry, it is clear that the wider continuum bandwidths of the EVLA will require a fully non‐linear and frequency‐dependent treatment of instrumental polarization calibration to minimize the associated closure errors and reach the dynamic range (for bright sources) implied by the advertised EVLA sensitivity. Such detailed instrumental polarization calibration has been rarely required at the sensitivities of the current instruments, and a linearized, frequency‐independent instrumental polarization

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solution has sufficed for most observations. In fact, the non‐linear solution is analytically not possible for the stand‐alone VLA due to its small geographical size (and thus lack of differential field‐of‐view orientation among antennas); the resulting polarization solution is a relative one, appropriate only for approximate calibration of linear polarimetry. Coordinated observations with the VLBA (and eventually, the New Mexico Array) enable, by virtue of greater geographical distribution of antennas, an unambiguous absolute instrumental polarization solution. The resulting higher dynamic range in total intensity (as well as linear polarimetry) also implies improved prospects for astronomical circular polarimetry, which have been notoriously difficult at the VLA in the past. This study is the first step in consideration of the differentially polarized field‐of‐view of the VLA/EVLA, which will be an important consideration for high dynamic range across wide fields of view. These advances in instrumental polarization treatment have corresponding importance for ALMA, an instrument which will make polarimetry at millimeter wavelengths routine for the first time.

In the next year, further research and development towards imaging in the presence of direction dependent effects using large bandwidths (e.g. the EVLA) will be carried out. To reach the kind of sensitivities possible with the EVLA and ALMA will require corrections for many direction dependant effects such as the effects of primary beam, antenna pointing offsets, varying primary beam sidelobes, wide band‐width effects etc; all these effects must be incorporated during imaging. The ground work research for new algorithms for imaging and solving for such effects and the associated software development will be the focus of research during the next year.

In the following year, a paper defining the nomenclature to be used in FITS for spectral world coordinates will be published and adopted by the IAU as a standard.

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Research Staff

Resarch Staff with Tenure

T. S. Bastian ‐ Solar/stellar radiophysics, flares, coronal mass ejections, solar chromosphere, radio propagation in the interplanetary medium; radio interferometry; Frequency Agile Solar Radio telescope (FASR) planning; Astronomer.

A. H. Bridle ‐ Extragalactic radio sources; Data Management scientific support; intersite communications support; grad student and visiting scientist support; Astronomer.

C. Carilli ‐ Galaxy formation, radio galaxies, QSO absorption lines, epoch of reionization; VLA support, ALMA planning, SKA planning; Astronomer.

J. J. Condon ‐ Nearby galaxies, evolution of star formation, radio surveys; Project Scientist, GBT precision telescope control system; Astronomer.

W. D. Cotton ‐ Extragalactic radio sources, interferometry, computational techniques for data analysis; scientific support: NRAO sky surveys and VLBI, Scientist/Astronomy.

J. R. Fisher ‐ Cosmology, signal processing, and antenna design; advanced receiver development; Scientist/Research Engineer.

E. B. Fomalont ‐ Astrometry, X‐ray binaries, deep imaging, relativity tests, VSOP and RadioAstron coordination, VLBA support, AIPS++ testing; Astronomer.

D. A. Frail ‐ gamma ray bursts, soft gamma ray repeaters, pulsar/supernova remnant associations, pulsar wind nebulae, masers, HI absorption and interstellar scattering; Astronomer.

W. M. Goss ‐ Galactic Center studies, Galactic Masers, pulsars, supernova remnants and nearby galaxies; Head of Division of Science and Academic Affairs; Astronomer.

K. I. Kellermann ‐ Radio galaxies, quasars, cosmology, SKA design, and radio telescopes; Head of New Initiatives; Sr Scientist/Astronomy.

A. R. Kerr ‐ Millimeter‐wave receiver development; SIS mixer design ‐ ALMA Project; Scientist/Sr Research Engineer.

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H. S. Liszt ‐ Molecular lines, mm‐wave absorption line spectroscopy, diffuse clouds, the galactic center and galactic structure; manager of NRAO’s foreign telescope travel support program, and director of NRAO’s spectrum management activities; Astronomer.

K. Y. Lo ‐ Galactic Center, star formation in dwarf galaxies, star‐burst galaxies and high redshift galaxies, mega‐masers and AGN, intergalactic medium, microwave background radiation, millimeter‐ and submillimeter‐wave interferometry; Director; Distinguished Astronomer.

F. J. Lockman ‐ Galactic structure, interstellar medium, and H II regions; GB education and outreach, GBT scientific support; student programs; Astronomer.

S. Myers ‐ Cosmology, cosmic background radiation, gravitational lenses, astronomical imaging; AIPS++ Project Scientist, ALMA and VLA/EVLA scientific support, algorithm development; Astronomer.

P. J. Napier ‐ Antenna and instrumentation systems for radio astronomy; EVLA Project Manager; Scientist/Sr Research Engineer.

F. N. Owen ‐ Clusters of galaxies, radio galaxies, deep continuum surveys; EVLA; Astronomer.

R. A. Perley ‐ Radio galaxies, QSOs, and interferometer techniques; EVLA Project Scientist/Astronomy.

D. S. Shepherd ‐ Star formation; molecular outflows; disks around luminous young stellar objects; molecular chemistry; millimeter interferometry and mosaic techniques; Astronomer.

B. E. Turner ‐ Galactic and extragalactic interstellar molecules, interstellar chemistry, and galactic structure; Astronomer.

J. M. Uson ‐ Cosmology, dark matter, clusters of galaxies, superthin galaxies; EPO scientist; spectral synthesis imaging; Astronomer.

P. A. Vanden Bout ‐ Interstellar medium, star formation, high‐redshift molecular emission galaxies, galaxy formation/evolution; Sr Scientist/Astronomy.

H. A. Wootten ‐ Star formation, structure and chemistry of the ISM in galaxies, and circumstellar material; ALMA Project Scientist.

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Tenure Track Astronomers

B. S. Mason ‐ Cosmology & Cosmic Microwave Background; high frequency instrumentation development for the GBT.

S. M. Ransom ‐ Pulsar searches and timing (especially binary and millisecond pulsars); GBT pulsar infrastructure improvement.

M. P. Rupen ‐ X‐ray binaries and transient sources; supernovae; interstellar medium; VLA and EVLA scientific support.

Scientist/Astronomy

D. S. Balser ‐ Galactic structure and abundances, H II regions, and planetary nebulae; GBT scientific support.

R. C. Bignell ‐ Planetary nebulae, polarization, cooling flow clusters, GBT scheduling.

J. Braatz ‐ Cosmic masers, active galaxies, molecular gas in AGNs, scientific software and algorithms, GBT science support.

B. J. Butler ‐ Planetary astronomy; EVLA System Engineer for Software.

C. Chandler ‐ Star formation, circumstellar disks, protostellar outflows, millimeter‐wave interferometry; VLA scientific support.

M. J. Claussen ‐ Masers, young stellar objects, AGB stars, protoplanetary nebulae, spectropolarimetry, VLA+Pt link support, VLA and VLBA scientific support.

V. Dhawan ‐ Radio and X‐ray observations of microquasars; VLBA astrometry, VLBA user support and EVLA testing.

D. T. Emerson ‐ Nearby Galaxies. Millimeter‐wave techniques and instrumentation. Spectrum Management. Chair of NA ALMA Technical Advisory Committee, and of the Observatory Technical Council.

F. D. Ghigo ‐ X‐ray binaries, AGNs, interacting galaxies; GBT scientific support (VLBI).

E. J. Hardy ‐ Galaxies, Cosmology, Stellar Populations, NRAO/AUI Scientist and Representative in Chile.

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Appendix B

J. E. Hibbard ‐ Extragalactic HI, gala xy evolution, and merging galaxies; spectral synthesis imaging; software testing.

P. R. Jewell ‐ Interstellar molecules, molecular spectroscopy; Deputy Director.

G. I. Langston ‐ Gravitational lenses, Galactic Plane Transient Surveys and searches for Extra‐ Solar Planets; GBT scientific support.

R. J. Maddalena ‐ Molecular clouds, galactic structure, interstellar medium; GBT scientific support.

J. G. Mangum ‐ Star formation, astrochemistry, and molecular spectroscopy of comets; ALMA.

M. M. McKinnon ‐ Pulsar astrophysics, radio polarimetry, statistics; Deputy Assistant Director, New Mexico Operations.

A. H. Minter ‐ Interstellar turbulence and galactic HI; GBT scientific support.

K. O’Neil ‐ Extragalactic gas and dust; low surface brightness galaxies; GBT technical and scientific support.

R. Prestage ‐ telescope performance and control; Project Manager, GBT Precision Telescope Control System; Interim Assistant Director, Green Bank Operations.

J. D. Romney ‐ Active extragalactic radio sources, interstellar medium, VLBI instrumentation; VLBA scientific support, VLBA Spacecraft Navigation Pilot Project manager, spectrum management.

L. O. Sjouwerman ‐ Circumstellar masers and AGB stars, centers of the Galaxy and Andromeda, VLBA data calibration and logistics, VLA/VLBA scientific support.

R. A. Sramek ‐ Normal galaxies, quasars, supernovae, and aperture synthesis techniques; ALMA.

J. S. Ulvestad ‐ Seyfert, LINER, and starburst galaxies, and extragalactic gamma‐ray sources; Assistant Director, New Mexico Operations.

R. C. Walker ‐ Extragalactic radio sources, VLBI and VLBA development; VLBA scientific support, EVLA and SKA design.

J. M. Wrobel ‐ Active galactic nuclei, sky patches at milliarcsec resolution; VLA/VLBA scheduling, GBT student support coordinator, phase calibrators for synthesis arrays.

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Appendix B

Q. F. Yin ‐ Normal galaxies and imaging techniques; NRAO sky surveys.

Scientist/Research Engineering

R. F. Bradley ‐ Millimeter electronics, low‐noise amplifiers, array receivers, adaptive RFI excision; advanced receiver development.

W. Brisken ‐ Pulsars, astrometry, disk‐based VLBI.

E. W. Bryerton ‐ Millimeter‐wave receiver development and HEB mixer research; ALMA local oscillator development.

J. Cheng ‐ Structural design and analysis, astronomical telescope design, sensors, carbon fiber material, and ALMA antenna development.

M. Morgan ‐ Millimeter‐wave MMIC design, MMIC‐based instrumentation, arrays, receiver component development for EVLA, GBT, ALMA, and SKA.

S. K. Pan ‐ Superconducting millimeter and sub‐millimeter wave low‐noise devices, circuits and receivers development; CDL.

J. M. Payne ‐ Telescope optics, millimeter‐wave receivers, metrology systems, and cryogenic systems; Local oscillator development ‐ ALMA.

M. Pospieszalski ‐ Microwave and millimeter wave low‐noise devices, circuits and receivers; CMBR radiometers; EVLA/VLBA/GBT/ALMA receiver development support.

K. Saini ‐ ALMA Local Oscillator Development, Frequency Multiplier Development, ALMA Front‐End System Engineering.

S. Srikanth ‐ Development of polarizers for mm wave applications and broadband prime focus feed at cm wavelengths; Scientist

J. C. Webber ‐ Instrumentaion development, program planning. Assistant Director for CDL, ALMA IPT Leader for Front End and Correlator.

Scientist/Computational Science

J. M. Benson ‐ Extragalactic radio sources, VLBA image processing; scientific support for VLA/VLBA correlator, develops and maintains the NRAO Science Data Archive and member of E2E‐EVLA Computing Group.

NRAO Program Plan ♦ FY 2006 251

Appendix B

S. Bhatnagar ‐ Supernova remnants, HII/UCHII regions, low‐frequency mapping of the Galactic plane, interferometric calibration and image reconstruction and related algorithm development; AIPS++.

K. Golap ‐ Wide‐field low‐frequency imaging; AIPS++.

E. W. Greisen ‐ Radio galaxies, HI in galaxies, interstellar medium, computer analysis of astronomical data, AIPS.

M. A. Holdaway ‐ Imaging methods, mosaicing, calibration, tropospheric transmission, site testing, simulations, operational optimization, configuration design, ALMA.

L. Kogan ‐ Maser radio sources; theory of interferometry; design of array configurations; AIPS group.

J. P. McMullin ‐ Star formation, interstellar medium, astronomical software systems; IPT Lead AIPS++.

A. J. Mioduszewski ‐ Microquasars, symbiotic stars, astrometry of young stellar objects; AIPS, VLBA and VLA support.

G. Moellenbrock ‐ Polarization interferometry and VLBI techniques, blazars, calibration and imaging algorithms and software for ALMA and EVLA, VLA and VLBA user support.

G. A. van Moorsel ‐ Dynamics of galaxies and groups of galaxies, and techniques for image analysis; Head ‐ New Mexico Computing.

Scientist/Emeritus

B. G. Clark ‐ EVLA control and software development; VLA/VLBA scheduling. Emeritus Scientist.

M. A. Gordon ‐ CO, galactic structure, gas‐rich galaxies, and interstellar medium. Emeritus Scientist. D. E. Hogg ‐ Structure of spiral galaxies; stellar winds; general support for the Directorʹs Office; Emeritus Scientist.

M. S. Roberts ‐ Emeritus Scientist.

A. R. Thompson ‐ Emeritus Scientist.

NRAO Program Plan ♦ FY 2006 252

Appendix B

Jansky Fellows

J. Aguirre ‐ Design and construction of millimeter‐wave instrumentation and data analysis for that instrumentation, with a focus on addressing problems in galactic evolution, cosmology, and the large scale structure of the universe; Jansky Fellow.

A. J. Baker ‐ Star formation and mass assembly at high redshift, starburst and active galaxies at low redshift, millimeter astronomy; Jansky Fellow.

P. Chandra ‐ Circumstellar interaction of supernovae with inputs from radio bands and X‐ray bands; Jansky Fellow.

S. Chatterjee ‐ Multi‐wavelength investigations of neutron stars, their distances, velocities, and relativistic winds; with an emphasis on high‐precision VLBA astrometry, which yields accurate parallax distances to radio pulsars; Jansky Fellow.

T. Cheung ‐ Multi‐frequency studies of jets in AGN; VLBI polarimetry; Jansky Fellow.

V. Fish ‐ Masers, high‐mass star formation; Jansky Fellow.

M. Haverkorn – Jansky Fellow.

N. Kanekar ‐ Galaxy formation, damped Lyman‐alpha systems, OH megamasers, structure of the ISM, the evolution of fundamental constants; Jansky Fellow.

Y. Y. Kovalev ‐ Extragalactic radio sources, single‐dish and VLBI; Jansky Fellow.

J‐P. Macquart ‐ Interstellar scintillation, structure of the ISM, Intra‐day variability, AGN polarization and structure, gravitational radiation; Jansky Fellow.

D. Meier ‐ The physical and chemical properties of nearby starburst galaxies; Jansky Fellow.

N. Miller ‐ Clusters of galaxies, multiwavelength studies of galaxy evolution; Jansky Fellow.

K. Spekkens ‐ Jansky Fellow.

NRAO Research Associates

L. Morgan ‐ NRAO Research Associate.

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Appendix B

B. Nikolic ‐ Heavily obscured star formation and AGN; galaxy evolution; sub‐mm/mm antennas; NRAO Research Associate.

A. Remijan ‐ NRAO Research Associate.

H. Voss – NRAO Reseach Associate.

D. Whysong ‐ NRAO Research Associate.

NRAO Program Plan ♦ FY 2006 254

Appendix C

Management Staff

Executive Management Group

Lo, K.Y. Director, Senior Scientist Jewell, Philip Deputy Director, Scientist Russell, Adrian NA Project Director for ALMA, NA ALMA Project Manager Clark, George Associate Director for Administration Hubbard, David Head of Program Management Office Goss, W. Miller Head of Division of Science and Academic Affairs, Scientist Adams, Mark Head of Education and Public Outreach Division, Special Assistant to the Director Kellermann, Ken Head of New Initiatives, Senior Scientist Condon, James Special Assistant to the Director

Administration

Clark, George Associate Director for Administration Bolyard, Jody Safety & Environmental Protection Manager, NA Executive Safety Representative DʹAngio, Robert Human Resources Manager Gibb, James Fiscal Officer Miller, Ted Business Manager Norville, Roy Deputy Human Resources Manager

ALMA

Russell, Adrian NA ALMA Project Manager Bolyard, Jody Safety & Environmental Protection Manager, NA Executive Safety Representative Davies, Antony NA ALMA Project Controller Glendenning, Brian NA ALMA Computing Division Head/IPT Leader, Scientist Hardy, Eduardo NRAO/AUI Representative in Chile, Scientist Janes, Clinton NA ALMA Backend Division Head/IPT Leader Perfetto, Antonio NA ALMA Project Deputy Division Head Pilleux, Mauricio Chile Business Manager Porter, William NA ALMA Business Manager, NA ALMA Deputy Program Manager Shepherd, Debra NA ALMA Computing Deputy Division Head, Scientist Simon, Richard NA ALMA JAO Project Controller, Scientist

NRAO Program Plan ♦ FY 2006 255

Appendix C

Sramek, Richard Deputy Assistant Director ALMA, Scientist, SSI IPT Leader Vanden Bout, Paul Head of NA ALMA Science Center, Senior Scientist Webb, Dale Tucson Business Manager Webber, John Assistant Director, Director of Central Development Laboratory, ALMA Correlator and Front End IPT Leader, Scientist, Senior Research Engineer Wootten, Al NA ALMA Science IPT Leader, Scientist Zivick, Jeff NA ALMA Antenna IPT Leader

Central Development Laboratory

Webber, John Assistant Director, Director of Central Development Laboratory, ALMA Correlator and Front End IPT Leader, Scientist, Senior Research Engineer Pan, Shin‐Kuo Deputy Assistant Director, Deputy Director of Central Development Laboratory, Scientist, Senior Research Engineer

Computing and Information Systems

Hunt, Gareth Head of Computing and Information Systems Murphy, Patrick Charlottesville Computing Division Head

Green Bank Operations

Prestage, Richard Interim Director Green Bank Operations, Scientist Anderson Jr., Robert Green Bank Telescope Operations Division Head Clark, Christopher Green Bank Computing Division Head Egan, Dennis GB Mechanical Engineering Division Head Ford, John GB Electronics Division Head Holstine, Michael Green Bank Business Manager Radziwill, Nicole GB Software Development Division Head

Program Management Office

Hubbard, David Head of Program Management Office Beverage, Charles Management Information Systems Manager

New Mexico Operations and EVLA Project

Ulvestad, James Assistant Director New Mexico Operations, Scientist Durand, Steven Socorro Electronic Division Head Golap, Kumar Science Software Group Deputy Project Manager, Associate Scientist

NRAO Program Plan ♦ FY 2006 256

Appendix C

Lagoyda, Skip Socorro Business Manager McKinnon, Mark Deputy Assistant Director New Mexico Operations, Scientist McMullin, Joe Science Software Group Project Manager, Scientist Napier, Peter EVLA Project Manager, Scientist Perley, Margaret Socorro Array Operations Division Head Robnett, James Socorro Computing Infrastructure Division Head Serna, Lewis Socorro Engineering Services Division Head Thunborg, Jon Socorro Engineering Services Deputy Division Head van Moorsel, Gustaaf EVLA Computing Division Head, Scientist

G. Clark, J. Bolyard, D. Hubbard, and J. Webber are listed twice owing to multiple roles.

NRAO Program Plan ♦ FY 2006 257

Appendix D

Committees

The NRAO Visiting Committee

The NRAO Visiting Committee is appointed by the AUI Board of Trustees to review the management and research programs of the Observatory. The Visiting Committee met in Charlottesville in 2005, Socorro in 2004 and 2003, and in Green Bank in 2002. The current committee membership and term dates are listed below.

Stefi Alison Baum, Rochester Institute of Technology 2008 Roger D. Blandford, Stanford Linear Accelerator Center (Recused) 2006 Roger J. V. Brissenden, Smithsonian Astrophysical Observatory 2006 John E. Carlstrom, University of Chicago 2006 Philip J. Diamond, Jodrell Bank Observatory 2005 Rodger Doxsey, Space Telescope Science Institute 2007 Paul T.P. Ho, Harvard‐Smithsonian Center for Astrophysics 2007 Reinhard Genzel, Max Planck Institute for Extraterrestrial Physics 2008 Douglas Lin, University of California, Santa Cruz 2008 George K. Miley, Leiden Observatory (2005 Chair) 2006 Philip Schwartz, Aerospace Corporation 2005 Eric E. Wilcots, University of Wisconsin 2005 Jonas Zmuidzinas, California Institute of Technology 2008

The Users Committee

The Users Committee is made up of users and potential users of NRAO facilities from throughout the scientific community. It advises the Director and the Observatory staff on all aspects of Observatory activities that affect the users of the telescopes. This committee, which is appointed by the Director, meets annually in May or June. The current committee membership and term dates are listed below.

Robert Becker, University of California, Davis Jan 2004 - 2008 Geoffrey Bower, University of California, Berkeley Jan 2004 - 2008 Tracy Clarke, Naval Research Laboratory Jan 2005 - 2009 Jeremy Darling, Carnegie Observatory Jan 2004 - 2008 Sean Dougherty, Dominion Radio Astrophysical Observatory Jan 2002 - 2006 Gary Fuller, University of Manchester Institute of Science and Technology Jan 2003 - 2007 Bryan Gaensler, Harvard University Jan 2004 - 2008 Andrew Harris, University of Maryland Jan 2002 - 2006 Jan Michael Hollis, NASA - GSFC Jan 2005 - 2009

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Appendix D

Deidre Hunter, Lowell Observatory Jan 2002 - 2006 Rob Ivison, UK Astronomy Technology Centre, Royal Observatory Jan 2005 - 2009 Chip Kobulnicky, University of Wyoming Jan 2003 - 2007 Stanly Kurtz, UNAM Jan 2003 - 2007 Cornelia Lang, University of Iowa Jan 2004 - 2008 Mary Putman, University of Michigan Jan 2004 - 2008 Daniel Stinebring, Oberlin College Jan 2005 - 2009 Michele Thornley, Bucknell University Jan 2003 - 2007 Stephen Thorsett, University of California, Santa Cruz Jan 2002 - 2006 Ed Wollack, NASA GSFC Jan 2003 - 2007 Lisa Young, New Mexico Tech Jan 2005 - 2009 Liese van Zee, Indiana University (2005 Chair) Jan 2002 - 2006

The Program Advisory Committee (PAC)

The Program Advisory Committee reviews and provides advice on the long range plan of the Observatory, on new programs and projects being considered for implementation, and on the priorities among Observatory program elements. The current committee membership and term dates are listed below.

Donald Backer, University of California, Berkeley Oct 1999 – 2005 Lee Mundy, University of Maryland Oct 1999 – 2005 Mark Reid, Center for Astrophysics Oct 1999 – 2005 Lawrence Rudnick, University of Minnesota (2005 Chair) Oct 2001 – 2006 Jean Turner, University of California, Los Angeles May 2005 – 2007 Eric Wilcots, University of Wisconsin Oct 2001 – 2006 Christine Wilson, McMaster University Oct 2001 – 2005 Min Yun, University of Massachusetts May 2005 – 2007

EVLA Advisory Committee

The EVLA Advisory Committee is to evaluate the EVLA Phase I project progress and requirements as well as the projectʹs future evolution should the opportunity to begin Phase II arise and advise the NRAO Director. Current membership terms expire 2006.

Anthony Beasley, Joint ALMA Office Fall 2004 ‐ 2006 Marco de Vos, Netherlands Foundation for Research in Astronomy Fall 2001 ‐ 2006 Sean Dougherty, NRC Herzberg Institute of Astrophysics Fall 2004 ‐ 2006 John Dreher, SETI Project Phoenix Fall 2001 ‐ 2006 Gianni Raffi, European Southern Observatory Fall 2004 ‐ 2006 Mark Reid, Harvard‐Smithsonian Center for Astrophysics (2005 Chair) Fall 2001 ‐ 2006

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Appendix D

Luis Rodriguez, Institute de Astronomia UNAM Fall 2001 ‐ 2006 Alan Rogers, Haystack Observatory Fall 2001 ‐ 2006 Stephen Scott, California Institute of Technology, OVRO Fall 2001 ‐ 2006 Tom Soifer, California Institute of Technology Fall 2004 ‐ 2006 Steve Thorsett, University of California, Santa Cruz Fall 2001 ‐ 2006 Jacqueline van Gorkom, Columbia University Fall 2001 ‐ 2006 Sander Weinreb, Jet Propulsion Laboratory Fall 2001 ‐ 2006

Observatory Computing Council (OCC)

The OCC will review computing issues from the Observatory‐wide perspective and advise the NRAO Director on what needs to be done, or the NRAO Director would ask the OCC to examine issues that should be reviewed. Current membership includes:

Bill Cotton, Chair Gareth Hunt Barry Clark Joe McMullin Ed Fomalont Nicole Radziwill Brian Glendenning Doug Tody Eric Greisen Mel Wright, University of California, Berkeley

Observatory Science Council (OSC)

The OSC will advise the Director on policy issues related to science and academic affairs at the NRAO. Specific issues include the policies and activities of the DSAA (Division of Science and Academic Affairs.)

Other issues include (i) the review of ideas for new telescopes, or new projects, and new instrumentation for existing telescopes; (ii) to stimulate the scientific environment for research throughout the NRAO, including the organization of research support for the scientific staff. Current membership includes:

Claire Chandler Ken Kellermann Jim Condon Fred Lo Dale Frail Steve Myers Miller Goss, Chair Frazer Owen Scott Ransom

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Appendix D

Observatory Technical Council (OTC)

The Council will advise the NRAO Director on technical issues that confront the Observatory, and will provide Observatory‐wide perspective and coordination in all technical areas, including future planning and R&D, current operations and problems, and projects such as the EVLA and ALMA. Current membership includes:

Darrel Emerson, Chair John Payne Barry Clark Marian Pospieszalski Rick Fisher Arthur Symmes Brian Glendenning Dick Sramek Tony Kerr Dick Thompson Peter Napier John Webber

ALMA North American Technical Advisory Committee (ANATAC)

The ANATAC is to report to the NRAO Director, who will feed findings back to the JAO and others, as appropriate. This small advisory group was created to perform an in‐ depth and end‐ to‐end look at the technical progress of the ALMA construction, on the North American (NA) side. This will be a standing committee, but may or may not need to be active at all times. Current membership includes:

Darrel Emerson, Chair Marian Pospieszalski Barry Clark Dick Sramek Peter Napier Arthur Symmes John Payne Dick Thompson

NRAO Program Plan ♦ FY 2006 262

Appendix E

Acronyms and Abbreviations

Acronym Definition AANM Astronomy and Astrophysics in the New Millenium AAS American Astronomical Society ACA ALMA Compact Array ACS Advanced Camera System ACS ALMA Common Software AGN Active Galactic Nucleus, or Active Galactic Nuclei AIPS Astronomical Image Processing System AIPT Antenna Integrated Product Team AISI American Iron and Steel Institute ALMA Atacama Large Millimeter Array ALMA‐J ALMA Japan AMC’s Active Multiplier Chains APRC Astronomy Performance Review Committee AOC Array Operations Center AOS Array Operations Site APEX Atacama Pathfinder Experiment ARCs ALMA Regional Centers ASAC ALMA Scientific Advisory Committee AST Astronomical Sciences (Division of the NSF) ASTE Atacama Submillimeter Telescope Experiment ASTRID Astronomerʹs Integrated Desktop ATA Allen Telescope Array ATCA Australian Telescope Compact Array ATF Antenna Test Facility ATI Advanced Technologies and Instrumentation AUI Associated Universities, Incorporated AZ Azimuth BAL Broad absorption line BEIPT Backend IPT BIMA Berkeley‐Illinois‐Maryland Array BW Bandwidth BYU Brigham Young University CARMA Combined Array for Research in Millimeter‐wave Astronomy CBI Cosmic Background Imager CASCA Canadian Astronomical Society CASA Common Astronomy Software Applications CCAT Caltech–Cornell Atacama Telescope

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Appendix E

Acronym Definition CCB Caltech Continuum Backend CCS Dicarbon Monsulphide Molecule CCE Common Computing Environment CDFS Chandra Deep Field South CDL Central Development Laboratory CDR Critical Design Review CGRO Compton Gamma‐Ray Observatory CIPT Computing IPT CIS Computing and Information Services CMBR Cosmic Microwave Background Radiation CO Carbon Monoxide CoI Co‐Investigator Con X Constellation X‐ray Observatory CORF Committee on Radio Frequencies (National Academy of Engineering) CSC Computing Security Committee CSO Caltech Submilimeter Observatory CVR Central Variable Reference CWVR Compact Water Vapor Radiometer CY Calendar Year DASI Degree Angular Scale Interferometer DDP Design and Development Plan DME Distance Measuring Equipment DOE Department of Energy DRAO Dominion Radio Astrophysical Observatory DSAA Division of Science and Academic Affairs DTS Data Transmission System e2e End‐to‐End EALMA Enhanced ALMA EMG Emission Galaxy EoR Epoch of Reionization EOS Equation Of State / Earth Orbital Synthesis EPO Education and Public Outreach ES&S Environmental Safety and Security ESO European Southern Observatory EVLA Expanded Very Large Array ETS Electronic Timecard System EUV Extreme Ultraviolet EVLA I Phase I of the EVLA EVLA II Phase II of the EVLA EVN European VLBI Network

NRAO Program Plan ♦ FY 2006 264

Appendix E

Acronym Definition FASR Frequency‐Agile Solar Radiotelescope FCC Federal Communications Commission FEIC Front End Integration Center FEIPT Front End Integrated Product Team FETMS Front End Test and Measurement System FIFO First in First Out FIR Far Infrared FIRST Faint Images of the Radio Sky at Twenty centimeter FITS Flexible Image Transport System FO Fiber Optics FPA Focal Plane Array FPGA Field‐programmable Gate Array FTE Full Time Equivelant FTS Federal Telecommunications Service FY Fiscal Year GaAs Gallium Arsenide GALEX Galaxy Evolution Explorer GASP Green Bank Astronomical Signal Processor GB/SRBS Green Bank Solar Radio Burst Spectrometer GBT Green Bank Telescope GCL Galactic Center Lobe GHz Gigahertz GEAR UP Gaining Early Awareness and Readiness for Undergraduate Programs Gb Gigabit GLAST Gamma‐ray Large‐Area Space Telescope GLIMPSE Galactic Legacy Infrared Mid‐Plane Survey Extraordinaire GMRT Giant Metrewave Radio Telescope GOODS Great Observatories Origins Deep Survey GP‐B Gravity Probe B GPS Global Positioning System GR General Relativity GRB Gamma‐Ray Burst GSA General Services Administration GSFC Goddard Space Flight Center GSMS Governor’s School for Mathematics and Science GSMT Giant Segmented Mirror Telescope HCN Hydrogen Cyanide HEB Hot Electron Bolometer HEMT High Electron Mobility Transistor HFET Heterostructure Field Effect Transistor

NRAO Program Plan ♦ FY 2006 265

Appendix E

Acronym Definition HIA Herzberg Institute of Astrophysics HR Human Resources HRIS Human Resources Information System HSA High Sensitivity Array HST Hubble Space Telescope HUDF Hubble Ultra Deep Field IAU International Astronomical Union ICD Interface Control Document ICRF International Celestial Reference Frame IDL Interactive Data Language IF Intermediate Frequency IFDC Intermediate Frequency Down Converter IGM Intergalactic Medium IMBH Intermediate‐mass Black Hole InP Indium Phosphide IPS Integrated Project Schedule IPT Integrated Prduct Team IR Infrared IRAM Institut de Radioastronomie Millimetrique IRDCs Infrared dark clouds ITU International Telecommunications Union IVOA International Virtual Observatory Alliance ISM Interstellar Medium JAO Joint ALMA Office JCMT James Clerk Maxwell Telescope JPL Jet Propulsion Laboratory JWST James Webb Space Telescope LAAS Local Area Augmentation System LAN Local Area Network LANL Los Alamos National Laboratory LCDM Lambda Cold Dark Matter LFA Low‐frequency Array LIGO Laser Interferometer Gravitational‐wave Observatory LNA Low Noise Amplifier LO Local Oscillator LSA Large Southern Array LSST Large Synoptic Survey Telescope LWA Long‐Wavelength Array LWDA Long‐Wavelength Development Array MAMBO Max Planck Millimeter Bolometer

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Appendix E

Acronym Definition M&C Monitor and Control MERLIN Multi‐Element Radio Linked Interferometer MHz Megahertz MIS Management Information Services Mm Millimeter MMA Millimeter Array MMIC Monolithic Microwave Integrated Circuit MOJAVE Monitoring of Jets in Active Galaxies with VLBA Experiments MOU Memorandum of Understanding MREFC Major Research Equipment and Facilities Construction MRI Major Research Instrumentation MSP Milli‐second Pulsar MSX Midcourse Space Experiment MUX Multiplexer NA North American / Not Applicable / Not Available NAASC North American ALMA Science Center NAIC National Astronomy and Ionosphere Center NAPO North American Project Office NAOJ National Astronomical Observatory of Japan NAS National Academy of Science NASA National Aeronautics and Space Administration Nb Niobium NCSA National Center for Supercomputing Applications NDFWS NOAO Deep Wide‐Field Survey NED NASA/IPAC Extragalactic Database NGAST Next Generation Archive Systems Technologies NGST Northrup Grumman Space Technology NINS National Institute of Natural Sciences NIST National Institute of Standards and Technology NOAO National Optical Astronomy Observatory NRAO National Radio Astronomy Observatory NRC National Research Council NRL Naval Research Laboratory NRQZ National Radio Quiet Zone NSF National Science Foundation NTC NRAO Technology Center NTT New Technology Telescope NVO National Virtual Observatory NVSS NRAO VLA Sky Survey O&M Operations and Maintenance

NRAO Program Plan ♦ FY 2006 267

Appendix E

Acronym Definition OCC Observatory Computing Council OH Hydroxyl Radical OIr Optical/Infrared OMP Orthogonal Modes of Polarization OOF Out of Focus OPM Observatory Program Management OPM3 Organizational Project Management Maturity Model OSC Observatory Science Council OSF Operations Support Facility OTC Observatory Technical Council OVRO Owens Valley Radio Observatory P2P Procure to Pay PAPER Precision Aray to Probe the Epoch of Reionization PAR Penn Array Receiver PI Principal Investigator PDR Preliminary Design Review PIO Public Information Officer PK Post‐Keplerian PMA Program Management Assessments PMCS Project Management Control System PMI Project Management Institute PMO Program Management Office PNE Planetary Nebula PPC Pre‐protostellar core PPDR Pre‐Production Design Review PRL President’s Request Level PSI Prototype System Integration PSP Program Standards and Processes PST Proposal Submission Tool PTCS Precision Telescope Control System PTE Part Time Equivelant QSO Quasi‐stellar Object R&D Research and Development RATAN Radio Telescope Antenna RET Research Experiences for Teachers REU Research Experiences for Undergraduates RF Radio Frequency RFI Radio‐Frequency Interference RHIC Relativistic Heavy‐Ion Collider RQQ Radio quiet quasars

NRAO Program Plan ♦ FY 2006 268

Appendix E

Acronym Definition RSI Research Systems, Inc. RXTE Rossi X‐Ray Timing Explorer SAO Smithsonian Astrophysical Observatory SB Scheduling Block SCO Santiago Chile Office SCOPE Southwest Consortium of Universities for Public Education SCUBA Submillimeter Common‐User Bolometer Array SDM Science Data Model SDSS Sloan Digital Sky Survey SE&I System Engineering and Integration SED Spectral Energy Distribution SEF Site Erection Facility SHARC Submillimeter High Angular Resolution Camera SIA Simple Image Access SIM SIM PlanetQuest (formerly Space Interferometry Mission) SIS Superconductor–Insulator–Superconductor SKA Square Kilometre Array SMBH Super‐massive Black Hole SNAP Supernova / Acceleration Probe SOFIA Stratospheric Observatory for Infrared Astronomy SOI Silicon on Insulator SPRC Scientist Performance Review Committee SQL Structured Query Language SQUID Superconducting QUantum Interference Device STARRS Panoramic Survey Telescope and Rapid Response System STARTEC State of the Art Telescope Educational Consortium STScIOPO Space Telescope Science Institute Office of Public Outreach submm submillimeter SWAN Survey of a Wide Area with NACO SWC Southwest Consortium SWG Simulations Working Group SZ Sunyaev–Zeldovich SZA Sunyaev–Zeldovich Array SZE Sunyaev–Zeldovich Effect TB Technical Building TDP Technology Development Program TES Transition Edge Superconducting TFB Tunable Filter Bank ToO Target of Opportunity UAz University of Arizona

NRAO Program Plan ♦ FY 2006 269

Appendix E

Acronym Definition UCBD Ultracompact Blue Dwarf ULX Ultraluminous X‐ray UNAM Universidad Nacional Autonoma de Mexico UNM University of New Mexico UV Ultraviolet UVA University of Virginia UVML Microfabrication Laboratory at the University of Virginia VERA VLBI Exploration of Radio Astronomy VHF Very High Frequency VLA Very Large Array VLBA Very Long Baseline Array VLBI Very Long Baseline Interferometry VLSS VLA Low‐frequency Sky Survey VO Virtual Observatory VSA Very Small Array VSOP VLBI Space Observatory Program WBBS Web‐Based Business Services WBS Work Breakdown Structure WCS World Coordinate System WHT William Herschel Telescope WIDAR WIdeband Digital INterferemtric ARchitecture WMAP Wilkinson Microwave Anisotropy Probe WRC World Radiocommunications Conference WSRT Westerbork Synthesis Radio Telescope WVR Water Vapor Radiometer YSO Young Stellar Object XMM X‐ray Multi‐Mirror Telescope

NRAO Program Plan ♦ FY 2006 270