Proposal Review and Science Program Science and Review Proposal 17 Cycle S instrumental commissioning SM4 following instrumental proposals in observing for available were instruments six All [FGS]). Sensor Guidance Fine [NICMOS], continuing instruments (Near-Infrared Camera and Spectrograph Multi-Object two and [STIS]), Spectrograph ImagingTelescope Space [ACS], Surveys for nhsatcly sbitn a oa o 98 rpsl b te ac 7 March the by proposals 958 of deadline, total an increase of 138 a over the Cycle 16 totals. responded submitting community the enthusiastically, that surprise a not therefore was It in 13. STIS Cycle of demise the since for spectroscopy high-resolution opportunity andfirst the medium- offer also will ACS—but revitalized a and new WFC3 the imaging—with by power discovery in improvement of-magnitude “..now sitsExpectationintheair...” Neill Reid Neill The post-SM4 suite of instruments will not only provide over an order- an over provide only not will instruments of suite post-SM4 The new instruments (Wide Field Camera 3 [WFC3], Cosmic Origins Origins Cosmic [WFC3], Spectrograph 3 [COS]), two restored instruments (Advanced Camera Camera Field (Wide instruments new are expectations that and hopes our mission, that of conclusion the At 2009. early in Center Space Kennedy the from launch for slated 4 Mission (SM4) to ervicing the , [email protected] Hubble Hubble will be at the peak of its capabilities—with two Cycle 17, which will start immediately after the the after 17, Cycle immediately start will which — HenryV, II,Chorus,I Hubble Space Telescope . VOL 25 http:// andM.Livio(STScI) ESA, Image Credit:NASA, Hubble is currently currently is ISSUE Hubble UnveilsColorfulandTurbulent Star-Birth Regionon100,000thOrbit Milestone site.org/newscenter/archive/releases/2008/31/ the Large, Treasury and Legacy programs. proposals Researcher the panels completed their after deliberations, Archival and met Observer it TAC graded The and $150,000. than General less for orbits programs 100 programs: than smaller less the rank for to days three first the 2007, October/November in about recruited seven months before were the meeting itself. members In May, TAC the panels met and over panelists Most UA). (IoA, Kennicutt Rob chair, TAC the and members at-large three included TAC also The (TAC). Committee Allocation Time the on served also The remaining ten panels were split equally between Galactic and and Galactic between “Galactic.” considered are galaxies nearby in populations stellar equally resolved of split observations purposes, assignment were For topics. extragalactic panels ten remaining The formation. star and disks, circumstellar devoted exoplanets, panels System, Solar two the towith doing panel In System 12. Solar to 11single the from replaced panels we so, of number the expanded we First, time. assigning of process the to changes of number a made we cycle, Process Review Peer proposals 17 Cycle the andtodirector.maderecommendationsthe all—assessed in community—124 astronomical SpaceTelescope Institute Science In Cycle 17, each panel had ten members, including the panel chair, who who chair, panel the including members, ten had 17,panel Cycle each In To allow for the expected increase in the number of proposals in this this in proposals of number the in increase expected the for allow To worldwide the from drawn astronomers 2008, 12–16, May On 02

Continued Hubble page 2 page

SUMMER 2 0 0 8 Hubble Update Kenneth Sembach, [email protected]

n September 27, 2008, Hubble’s Control and Data Handling (C&DH) system experienced a problem that led to the safing of the science instruments. At the Otime this Newsletter goes to press, it appears that the problem is in the hardware, inside a unit called the Control Unit/Science Data Formatter (CU/SDF). The CU/SDF is an essential element for the operation of the existing instruments—WFPC2, NICMOS, ACS, and STIS—and it will be needed for COS and WFC3 when they are installed. The CU/SDF NASA stores and controls commands received by the instruments, buffers and formats science data, and sends the data to the communications system for transmission to Earth. There have been no previous failures in the CU/SDF or its associated electronics since launch in 1990. A second CU/SDF is presently onboard Hubble. Engineers and a review board are examining what it will take to return Hubble to service using this back-up hardware. In the meantime, Hubble continues to execute science programs with its Fine Guidance Sensors. Given the importance of the CU/SDF to the operation of the science instruments, NASA may determine that it is necessary to install spare C&DH hardware, which would likely delay Servicing Mission 4 until 2009. We will post updates to the Hubble website (http:// www.stsci.edu/hst/) as information becomes available.

Each panel covered a broad science area, making it imperative for proposers to write lucidly for Cycle 17 non-specialists. from page 1 With multiple panels in each area, we could redirect proposals where a panelist had a conflict of interest to a mirror panel in the same subject area. By this means, while institutional and personal conflicts still arose, we avoided major conflicts. Even so, for some proposals the growing size of astronomical collaborations could lead to our disqualifying a majority of the panel were we to strictly interpret conflict-of-interest rules. In response to this situation, we adjusted the specific

Results from the TAC Questionnaire YES NO No. of No. of respondents respondents

1. This year we moved the location of the TAC review from the BWI Marriott hotel to 52 (90%) 6 (10%) the Homewood campus. Did you find the location conducive to the TAC process?

2. If you have experience of previous TAC meetings, which location is preferable?

BWI Marriott: 7 (25%) JHU: 21 (75%) 3. In your opinion, what aspects of the TAC logistics worked well, and what [48 responses] aspects worked less well? 4. Could you find the answer to most of your questions in the documentation available 56 (97%) 2 (3%) to panelists (CP and/or guidelines)? 5. Was the information that you required for the review well organized? 46 (79%) 12 (21%) 6. Did you feel you had the appropriate expertise to review the proposals assigned to you? 53 (90%) 6 (10%) 7. Did you feel the panel as a whole had the appropriate expertise? 51 (86%) 8 (14%) 8. Do you feel that you were able to contribute effectively to the panel discussions? 57 (97%) 2 (3%) 9. This year we modified our procedures for dealing with conflicts of interest. 51 (88%) 7 (12%) Do you feel that the revised system strikes the right balance? 10. This year we experimented with a new web-based system for collecting the comments on proposals. How well do you feel that the system worked? Very poorly: 3 (5%) Somewhat well: 32 (53%) Somewhat poorly: 13 (22%) V ery well: 12 (20%)

2 ProposalsProposals by Countryby Country GO Proposal oversubscription Coun try SubmittedApproved GO Orbit oversubscription 9.00 AR Funding oversubscription Australia 3 0 Belgium 6 1 8.00 Canada 15 5 Chile 4 0 France 19 6 7.00 Germany 32 7 Ireland 5 1 6.00 Israel 2 0 Italy 16 4 5.00 Japan 1 0 Mexico 31 Netherlands 10 3 4.00 Poland 1 0 Russia 2 0

Oversubscription Ratio 3.00 Spain 19 1 Sweden 4 0 2.00 Switzerland 7 1 Cycle 7 AR Extension UK 51 8 1.00 USA 758 190 ESA Proposals181 35 12345677N 8910 11 12 13 14 15 16 17 Cycle Figure 1. Oversubscription ratios for Hubble over its lifetime. ProposalsProposals by State by State

State SubmittedApproved application of those rules for panelists who were collaborators with proposal co-investigators. We distinguished two types of conflict: major conflicts, where the panelist was required to leave AL 5 1 the room for the full discussion; and minor conflicts, where the panelist declared the conflict and AR 1 0 participated in the discussion, but did not vote. AZ 54 13 In past years, we have defined as major conflicts those situations where a co-investigator on a CA 152 37 proposal is a close collaborator of a panelist. This year we relaxed that criterion, redefining these Co-I CO 26 6 CT 9 3 close-collaborator conflicts as “minor conflicts.” This allowed the panels to discuss some proposals DC 34 2 without eliminating all the relevant experience in that particular science area. A “close collaborator” DE 5 0 is a colleague with whom one is (1) actively collaborating on a current research program, including FL 21 2 a current-cycle Hubble program; (2) an active collaborator on three or more completed research GA 9 3 programs within the last three years; or (3) an active co-author on three or more papers within the HI 19 5 IA 1 0 last three years. Amplifying on the last criterion, we define an “active co-author” as a colleague IL 24 4 with whom the panelist has communicated directly in the course of writing a paper; nowadays IN 8 4 there are many large collaborations where team members have authorship rights, and may appear KY 8 0 as co-authors with other astronomers whom they have never met (sleeping collaborators?). LA 3 1 MA 26 13 A third major change in Cycle 17—and most obvious for the participants—was the venue for MD 130 34 the TAC. MI 26 8 In the early years of Hubble, the TAC met at the Institute. However, the large number of separate MN 7 1 panels (and smaller number of meeting rooms) required spreading the process over a two-week NH 6 4 period. Starting in Cycle 11, the TAC moved to a local hotel equipped with sufficient conference NJ 13 4 NM 9 2 rooms to complete the process in a single week. For a variety of reasons, this option became NV 4 0 untenable, and the Cycle 17 TAC moved back to the Homewood campus of the Johns Hopkins NY 46 9 University, where the Institute is located. The Institute itself still lacks enough rooms to cope with OH 20 5 12 simultaneous panel meetings, but the JHU Physics and Astronomy department kindly offered OK 2 1 additional space. OR 1 0 PA 23 10 With the panels on site, we were able to use a secure, web-based system for collecting their SC 3 0 comments on the individual proposals. This system was completed only a few days before the TAC TN 4 0 meeting. In future, we plan to make this system available to panelists well before the meeting itself. TX 20 7 In light of all these changes, we made a point of circulating a questionnaire to gather feedback UT 1 0 VA 12 3 from TAC and panel members. We received a total of 58 responses (numerical results are presented VT 1 1 in the sidebar); by and large, the feedback was favorable. The change in venue WA 18 6 was well received, with only a few panelists expressing lingering nostalgia for Continued WI 4 1 the BWI Marriott. Respondents identified a number of areas for improvement, page 4 WY 2 0

3 ESA Acceptance Fraction including: details of the catering; Cycle 17 40% complexity in the panel guidelines from page 3 and travel documentation; access 28.5% to the web-based comment system; 30% 28.0% 26.7% the number of proposals per panel; 26.1% and the distribution of science 25% 24.5% 22.1%

categories. We will address these 22.9% 20.3% 19.6%

issues in Cycle 18. 24.6% 18.7% 18.8%

20% 18.5% A typical 12-month Hubble cycle 13.9% 16.8% 16.8% 21.5% Accepted 15.4%

comprises approximately 3,000 19.6% 19.2% 18.6% 18.2%

orbits for Guest Observer (GO) 15% 13.0% 16.8% 16.6% 16.5% 16.1%

science programs. Cycle 17 will be 15.7% 15.1% 15.0% 15.6% significantly longer than 12 months, 10% but it must also accommodate the 12.6% 8.1% post-SM4 instrument verification Proposals 10.2% 5% phase, Early Release Observations Orbits (EROs), COS Guaranteed Time Observations (GTO) and WFC3 Early 0% Release Science observations. The 1 2345677N 8910 11 12 13 14 15 16 17 net result is that about 3,400 orbits Cycles were still available for GO programs in Cycle 17, with approximately Figure 2. ESA acceptance fraction over Hubble’s lifetime. two-thirds of the time allocated by the panels. The TAC and the panels ranked proposals a factor of two beyond the nominal orbit allocation to ensure an adequate reservoir for final deliberations. The final ranked lists of recommended programs were submitted to the Institute director for approval. Statistics The 958 proposals submitted in Cycle 17 comprised 750 GO programs (including 14 Treasury programs, 38 Large programs), 41 Snapshot programs, 22 Survey programs, 88 Archive programs, 4 Legacy Archive programs, and 53 Theory programs. There were 351 proposals for the Galactic panels, 431 for extragalactic, 116 for planetary systems, and 60 proposals for the TAC. In total, these proposals requested 20,771 orbits (an over-subscription of 6:1), 4,390 Snapshot targets, and ~$12 million in AR funding (both 4:1 oversubscriptions). The Cycle 17 panels and TAC recommended approving 228 programs, including 173 GO programs, 16 Snapshot programs, 26 Archival programs, 1 Legacy Archival program, and 12 Theory programs. These include 6 Calibration programs. As in Cycle 16, no Survey proposals were awarded time, and we will eliminate this category in Cycle 18. The TAC identified 14 Large and Treasury programs that merited Proposal Institutional Acceptance Fraction time, including three Pure Parallel programs, 100% one AR Legacy program, and one large SNAP program. 90% Hubble is a joint NASA/ESA mission. 80% Table 1 shows the distribution of submitted 70% and accepted proposals by country in Cycle 60% 17. ESA scientists were PIs on 35 of the 228 50% accepted proposals (15.4%), accounting 40% for 15.6% of the orbits allocated. This is a significant increase over Cycle 16 30% (Figure 2). Over Hubble’s lifetime, ESA 20% scientists have been PIs on 20.1% of the 10% proposals, responsible for 16.5% of the 0% total orbits. Moreover, the joint nature of

A California Institute of Ca Da Harvard University Jet Pr L Massachusetts Institute of Technology NASA Goddard Sp Northwestern University Ro Space Telesco The John The Ohio State Un The Pennsylvania State Un U U U University U U U Universit University Un U Ya merican Museum of Natu owell Observat niversity of Arizona niversity of California - Berkeley niversity of California - Los niversity of Colorado at Boulder niversity of Hawaii niversity of niversity of Wa rn rt ch l ive e University the Hubble science program is emphasized m egie Institution of Washington e outh o ster Institute of Technology rsity pulsion Laboratory

s y Hopkins Universit by the fact that ESA astronomers were

of California - Santa Cruz of Michigan of Notre Dame o C f Texas at Austin ollege Ma p e Science Institute o co-investigators on 88 proposals (38.5%), ryland s ry a hington ive ce Flight

rs Technology embracing 61% of the orbits allocated in i ty Research Foundation

r ive al History C y A Cycle 17. ente rsi ngeles

t y

r Table 2 provides the state-by-state

distribution for the U.S. proposals. Within the U.S., California and Maryland were the Figure 3. Proposal acceptance for U.S. Institutions. most awarded states (as in past cycles),

4 but Pennsylvania, New Hampshire, and, particularly, Vermont had higher acceptance rates in this cycle. Similarly, MIT should be commended for its perfect 4/4 record (Figure 3). (Note that we inadvertently omitted Iowa—with one accepted proposal—from these statistics in the Cycle 16 report; unfortunately, Iowa did not fare as well in the present cycle.) As might be expected, the two new instruments garnered most attention (and most orbits) in Cycle 17 (Figure 4). Overall, the split was 2:1 between imaging (66% of the orbits) and spectroscopy (31%), with the FGS accounting for the remaining time. Including coordinated parallels and pure parallels, WFC3 programs were allocated 46.1% of the time, with the WFC3 near-infrared (NIR) channel essentially replacing NICMOS, while ACS attracted 24.4%. COS was allocated 17.7% of the time, primarily in the far-ultraviolet channel, while STIS received 7.9% of the total orbits allocated by the TAC and panels. ACS and WFC also received the bulk of time allocated to the SNAP programs (666 and 614 targets, or 44.2% and 40.8%, respectively), with STIS gaining 9.3% of the targets, and the remainder divided equally between NICMOS and COS. Science Program The new instruments available in the coming cycle will open up new science areas, and the TAC mapped out a highly diversified scientific program for Hubble. Figure 5 compares the distribution of accepted proposals by science category in Cycle 17 against similar data for Cycle 16. Many subject areas show only modest change (e.g., cosmology and resolved stellar populations). Nevertheless, there is a distinct change in the flavor of the proposals. The categories of quasar absorption lines/ IGM and cool stars almost doubled in size (reflecting the availabilities of COS and STIS), while unre- solved stellar populations, AGN/quasars, and star formation showed declines in popularity. Cycle 17 will see a specific emphasis on the high-redshift universe. Combining the gains in sensitivity and areal coverage, the WFC3 NIR offers more than an order-of-magnitude improvement in discovery space over NICMOS, and several programs take advantage of these new capabilities. In addition to a NIR deep-field survey, centered on the Hubble Ultra Deep Field and reaching 29th magnitude (AB), two pure-parallel programs will use WFC3-NIR imaging to probe the z > 6 universe, while a third utilizes NIR grism spectroscopy to survey star formation from z ~ 0.5 to beyond z ~ 6. COS was designed to achieve high throughput spectroscopy, especially at far-UV wavelengths, with the particular goal of probing the structure of the intergalactic medium. Two large programs build on that potential, with both using QSOs at moderate redshifts (0.8 < z < 1.5) as background light sources. One program targets 43 z < 1 QSOs lying behind lower-redshift galaxies from the Sloan Digital Sky Survey (SDSS); the other program targets QSOs that lie in the outskirts of nearby low-redshift galaxies. Together, these programs will map the distribution of ionized baryonic material in galactic halos and the IGM. Cycle 17 has no accepted programs that directly address the enigma of dark energy, but several tackle ancillary questions. Thus, the TAC awarded time to a large SNAP program that will examine the host galaxies of SDSS-detected supernovas, with the aim of elucidating the character of the parent population and the likely nature of the supernova progenitor. Similarly, the panels awarded time to a medium program that looks to refine the current value of the Hubble constant, H0. Other programs aim to improve the globular cluster distance scale via higher-accuracy parallaxes for key nearby subdwarfs, to probe the age of 47 Tucanae by tracing the full extent of the cluster’s white-dwarf sequence, and to use multicolor imaging to disentangle the star-formation history of the Galactic bulge.

Proposal selection—an interesting statistic Over the past 17 cycles, we have used number of statistical parameters to keep track of the Hubble time-allocation process. One such statistic is the average size of approved programs. As Figure 6 shows, the present cycle demonstrates a sharp downturn in both the average and the median proposal size as compared with the previous two cycles. Figure 7 compares the distribution of program sizes for panel-allocated programs in Cycles 14 to 17; these distributions are normalized to the total number of GO programs. In each case, over 40% of the programs were allocated less than 10 orbits. Nevertheless, there was a noticeable increase in programs in the 10–20 orbit range from Cycle 16 to Cycle 17. Many of those programs utilize COS. Figure 7 also shows a decrease in the number of medium-sized programs between Cycles 16 and 17; indeed, there are only four programs in the 50–99 orbit range in Cycle 17, and two of those programs were allocated by the TAC. Panel proposals of this size are subsidized from a central pool, so a 30-orbit program “costs” a panel only about 24 orbits, while a 75-orbit program costs about 38 orbits. Astronomers in some disciplines, such as cosmology and stellar populations, have adapted to this system and make good use of the subsidy pool; others have been less effective. Part of the problem undoubtedly lies in the psychological barrier of assigning a large fraction of panel’s proposal allocation to a single proposal. In the present cycle, the “pain” Continued threshold lies near 20% of a panel’s orbit allocation. Even in the TAC, which had page 6 ~1100 orbits available, the largest accepted program required only 192 orbits. 5 Some disciplines exacerbate the situation by concentrating on small proposals—for example, Cycle 17 from page 5 the hot-stars and ISM panels accounted for 18% of the GO proposals, but less than 7% of the requested orbits. Because the panel allocations are based on averaging these two quantities, 12% of the panel orbits (300 orbits) were assigned directly to these two panels, setting the pain threshold at only 25–30 orbits. We are looking at ways of addressing this issue, perhaps through a realignment of science topics in Cycle 18. Cycle 18 and Multi-Cycle Treasury Programs The Cycle 18 schedule depends on the SM4 schedule. SM4 was recently delayed from October 2008 to early 2009. With the October launch date, Cycle 17 was set to run through the calendar year 2009. We have a full calendar of observations, so we have no intention of truncating the cycle. Once a new date for SM4 is set, we will inform the community of the revised Cycle 18 schedule. In the interim, we still anticipate issuing a call for Multi-Cycle Treasury (MCT) Programs. As discussed by the director in the fall 2007 Newsletter, the intention is to provide an opportunity for the community to propose very large (>500 orbit) programs that tackle key science questions that cannot be addressed through the standard TAC process. The call for MCT proposals will be issued after the completion of SM4, once it is clear what instrumentation will be available. We anticipate a two-stage MCT-selection process, with a Phase I deadline for written propos- als. Those proposals will be reviewed by a TAC, which will select a short list. Those programs will be developed, with technical assistance from the Institute, and reassessed before the final program selection, which will be made well before the Cycle 18 deadline, in order to allow the submission of Cycle 18 AR proposals to use data from MCT Programs. The orbits for any selected programs—and the MCT TAC will have the option of selecting no programs—will be drawn from those normally allocated to Large and Treasury programs. Full details on the MCT process will be circulated after SM4. Defining the science program of the Hubble Space Telescope is one of the most important responsibilities of the Institute. The community’s involvement in the TAC process is crucial, and we are indebted to the many panelists who devote their time and energy to evaluating proposals and providing feedback. We thank all of them, particularly the Cycle 17 TAC Chair, Rob Kennicutt, for their hard work and invaluable assistance in this task.

Acknowledgements Numerous Institute and JHU personnel contribute to the TAC process, some at the meeting itself, others behind the scenes. Within the Science Policies Division, Claus Leitherer and Eva Villaver were responsible for selecting the panelists, assigning the proposals to panels and panelists, and, assisted by Bob Williams and Marco Lombardi (ST-ECF), providing roving oversight at the TAC. Brett Blacker received, organized, and distributed the proposals, oversaw the proposal database, distributed the results, and prepared the statistical summaries and figures presented here. Greg Masci, John Kaylor, Craig Hollinshead, Leigh McEwan, and other members of the Information Technology Services Division were responsible for developing and implementing the web-based comment system. The Instruments Division and the Hubble Mission Office were responsible for technical support, and over 20 Institute postdocs and staff provided panel support: Tony Roman, Chris Blades, Alexis Cornysh, Will Clarkson, Tim Dolch, Ed Nelan, Francesca Annibali, Benne Holwerda, Galina Soutchkova, Danny Lennon, Julio Chaname, Anton Koekemoer, Aaron Grocholski, Elizabeth Barker, Gustavo Cardona, Paul Goudfrooij, David Radburn-Smith, Kevin Lindsay, Elena Sabbi, Helene McLaughlin, Luigi Bedin, and Susan Kern. Logistical support was a particular challenge this year, with our move back to the Homewood campus. Darlene Spencer provided the overall supervision, assisted by Catherine Riggs, Karen Keidel, Karen Petro, Flory Hill, Robin Auer, Shelly Marshall, Dixie Shipley, Loretta Willers, Tracy Lamb, Cheryl Schmidt, Roz Baxter, Debbie Brenner, Alicia Meizlish, Pam Rudisill, Kathy Hashim, Tania Laguerre, Pat Brown, Pam Turner, and Ronda Washington. Assistance on the JHU side was provided by Brian Schriver, Pam Carmen, and Norma Berry, while Mike Venturella, Frankie Schultz, Jeff Nesbitt, Will Smith, Greg Pabst, and Alford Kizer supplied Institute facilities support. Finally, Joe Hann, Karen Debelius, Vickie Bowersox, Yulanda Williams, Lisa Kleinwort, Amy Powell, and Ray Beaser in the Business Resources Center were also involved in the process. W

6 Approved Orbits by Science Category Approved Orbits by Science Category

3% 5% 2% 5% 3% 9% 5% ISM in External AGN/Quasars 6% 13% Galaxies Hot Stars 11% Cool Stars 5% ISM and 9% 19% 26% Cosmology Circumstellar Matter 6% Extra-Solar Planets Resolved Stellar 12% 5% 7% Quasar Absorptions Populations Lines and IGM 12% 12% 4% 9% 13% Unresolved Stellar Star Formation 5% 2% Populations and Galaxy Structures Solar System

Figure 5. A comparison between the distribution of accepted proposals by science category in Cycles 16 (left) and 17 (right); the categories are labeled clockwise from 12 o’clock.

Orbit Size by CycleOrbit Size by Cycle

35 Median submitted Median approved 30 Average submitted Average approved 25 10 15 Orbit size 10 5 0 67 7N 8910 11 12 13 161514 17 Cycle Orbit Bins by Cycle Orbit Bins by Cycle 50%

40%

30% Cycle 14 Cycle 15 20% Cycle 16 10% Cycle 17

Number of Proposals 0%

1 – 10 11 – 20 21 – 30 31 – 40 41 – 50 51 – 60 61 – 70 71 – 80 81 – 90 91 – 100 > = 100

Bins Cycle 17 graphics by Christian Lallo (STScI).

Tables continued on page 8

7 Instrument Statistics Cycle 17, Instrument Statistics from page 7 Instruments Mode Requested Orbits % Approved Orbits %

ACS/HRC Imaging 937 3.01% 180 3.4% Rampfilter 21 0.07% 0 Spectroscopy 131 0.42% 10 0.2% ACS/SBC Imaging 389 1.25% 34 0.6% Spectroscopy 7 0.02% 0 ACS/WFC Imaging 7914 25.41% 1007 19.7% Rampfilter 134 0.43% 22 0.4% Spectroscopy 280 0.90% 0 COS/FUV Spectroscopy 2486 7.98% 769 15.0% COS/NUV Imaging 89 0.29% 72 1.4% Spectroscopy 351 1.13% 66 1.3% FGS POS 460 1.48% 110 2.1% TRANS 13 0.04% 0 NICMOS/NIC1 Imaging 221 0.71% 35 0.7% NICMOS/NIC2 Imaging 995 3.19% 10 0.2% NICMOS/NIC3 Imaging 2672 8.58% 0 Spectroscopy 91 0.29% 24 0.5% STIS/CCD Imaging 100 0.32% 46 0.9% Spectroscopy 586 1.88% 188 3.6% STIS/FUV Imaging 3 0.01% 3 0.1% Spectroscopy 1011 3.25% 95 1.9% STIS/NUV Imaging 5 0.02% 0 Spectroscopy 573 1.84% 79 1.5% WFC3/IR Imaging 5707 18.32% 1247 24.4% Spectroscopy 535 1.72% 352 6.7% WFC3/UVIS Imaging 5389 17.30% 770 15.0% Spectroscopy 46 0.15% 0 31 146 5119

Mode1 Approved Orbits (%) Imaging 67.0% Spectroscopy 30.9% FGS 2.1%

1Includes Coordinated and Pure Parallels, but not Snapshot programs.

Instrument Approved Orbits (%) ACS 24.5% COS 17.8% FGS 2.1% NICMOS 1.3% STIS 8.0% WFC3 46.3%

8 Cycle 17: Approved Observing Programs ll-studied LBGs at z ~ 3 z = 2.84 b ung Galaxy in the Local Universe? Connection in Early-type Galaxies at Low X-ray Luminosities z < 1.5: H-alpha Fluxes and Sizes from a Grism Survey of GOODS-N pe II Supernovae with HST , Spitzer and Gemini Ty z = 7 Galaxy man Continuum -alpha + Metal Line Absorption Complex Near Two Galaxies at z = 0.67 -alpha + Metal Line Absorption Complex Near Two man Break Galaxy Analogs: New Clues to Formation in the Early Universe st of Accretion Physics with NGC 4203

AR Understanding the Fundamental Structure of Superwinds: An Archival Study of Clouds in M82's Wind Toward AR Research Foundation Studying Cepheid Systematics In M81: Archival BVI Data AR Structural Properties of Star Clusters in M33 AR AR Constraining the Star-formation and Metal-enrichment Histories of Galaxies with the Next Generation Spectral Library Comprehensive Theoretical UV-optical Diagnostics for STIS and COS AR The Stellar Metallicities of a Large Sample Dwarf Galaxies: Constraints on Formation Models AR Merging Supermassive Black Holes: Observational Consequences of Gravitational-radiation Recoils, Spin, and Gas Dynamics AR Star Clusters for Five Hundred Galaxies A Database of Young AR Modeling the Broad Lines of Nearby LLAGNs with Known Central Masses AR Spectroscopic Archive Legacy Survey of the Cosmic We GO Luminosity Profiles of Extremely Massive Clusters in NGC 7252 GO The Gaseous Corona of M31 GO The Black Hole Mass—Bulge Luminosity Relationship for the Nearest Reverberation-mapped AGNs GO A Fundamental Te GO A Definitive Distance to the Coma Core Ellipticals GO The Extremely Metal-poor BCD Galaxy DDO 68: A Yo GO Throughput Calibration of the 52 x 0.2E1 Aperture GO GO Opening New Windows on the Antennae with WFC3 Super Star Clusters in the Starburst Core of M82 GO Using Massive Star Clusters in Merger Remnants to Provide Reference Colors of Intermediate-age Stellar Populations GO GO Research Foundation Studying Cepheid Systematics in M81: H-band Observations The Stellar Halos of Dwarf Galaxies GO GO The Star Formation Rate in Nearby Elliptical Galaxies UV Spectroscopy of Local Ly GO The Nature of the Black Hole in a NGC 4472 Globular Cluster and Origin Its Broad [O III ] Emission GO The Impact of Starbursts on the Gaseous Halos Galaxies GO First Resolved Imaging of Escaping Ly GO Illuminating the H I Structure of a Proto-cluster Region at GO Improving the Radius-luminosity Relationship for Broad-lined AGNs with a New Reverberation Sample GO The Difference between Neutral- and Ionized-gas Metal Abundances in Local Star-forming Galaxies with COS GO Probing He II Reionization with GALEX -selected Quasar Sightlines and HST /COS GO GO Lensed Galaxies at z = 0.9 Resolved H-alpha Star Formation in Two Star Formation, Extinction, and Metallicity at 0.7 < GO Detailed Probing of a 3000 km/s Ly GO Probing The Globular Cluster/Low-mass X-ray Bina ry GO The LSD Project: Dynamics, Merging and Stellar Populations of a Sample We GO Probing Population III Star Formation in a GO of Universal Formation Efficiency The Extreme Globular Cluster System of Abell 1689: Ultimate Test SNAP The Nuclear Structure of OH Megamaser Galaxies SNAP GHOSTS: Stellar Outskirts of Massive Spiral Galaxies Type Type Title The Johns Hopkins University University of Cambridge University of California – Los Angeles Rochester Institute of Technology Rochester Institute of Technology University of Toledo University of Toledo University of California – Irvine Ohio University University of Hawaii Dominion Astrophysical Observatory NASA Goddard Space Flight Center Space Telescope Science Institute Space Telescope NASA Goddard Space Flight Center Space Telescope Science Institute Space Telescope Space Telescope Science Institute Space Telescope University of Michigan Laboratoire d'Astrophysique de Marseille Michigan State University GO Are Low-luminosity Galaxies Responsible for Cosmic Reionization? Space Telescope Science Institute Space Telescope Jet Propulsion Laboratory California Institute of Technology California Institute of Technology Rochester Institute of Technology Rochester Institute of Technology Max-Planck-Institut für Astronomie, Heidelberg The Ohio State University Research Foundation University of California – Irvine GO Quasar Host Galaxies at z > 6 Alpha Imaging of Two Lyman GO Profiles of Quasar Accretion Disks The Temperature Space Telescope Science Institute Space Telescope Astrophysikalisches Institut Potsdam Carnegie Institution of Washington Carnegie Institution of Washington Louisiana State University and A & M College GO A Comprehensive Study of Dust Formation in The University of Virginia INAF - IRA, Firenze Space Telescope Science Institute Space Telescope Embry-Riddle Aeronautical University University of Arizona Dominion Astrophysical Observatory University of Colorado at Boulder Institution Cycle 17: Approved Observing Programs Name Christopher Kochanek The Ohio State University David Strickland Nate Bastian Michael Rich Christopher Kochanek The Ohio State University David Axon Rupali Chandar Misty Bentz Joseph Shields Timothy Heckman The Johns Hopkins University Lisa Kewley John Blakeslee Sara Heap Alessandra Aloisi Mark Westmoquette Mark Westmoquette Sara Heap University College London Brad Whitmore Julianne Dalcanton Paul Goudfrooij University of Washington Timothy Heckman The Johns Hopkins University Julianne Dalcanton Joel Bregman University of Washington Dennis Crenshaw Georgia State University Research Foundation GO Are Narrow-line Seyfert 1 Galaxies Viewed Pole-on? Stephen Zepf Jean-Paul Kneib Roelof de Jong Brian Siana Charles Steidel Stefanie Komossa C. Kochanek Misty Bentz Max-Planck-Institut für extraterrestrische Physik GO Recoil Event Black Hole Superkicks: Imaging the Site of a Gravitational Wave Carlos Lousto Christopher Churchill Fabian Walter New Mexico State University Alessandra Aloisi Gabor Worseck Gabor Worseck Benjamin Weiner Benjamin Weiner University of Arizona Jane Rigby Jennifer Andrews Craig Sarazin Filippo Mannucci Brad Whitmore ExtraGalactic Programs Nick Devereux Xiaohui Fan John Blakeslee Michael Shull Archive Legacy Programs

9 Cycle 17: Approved Observing Programs alpha Systems - CR L3068 ak Lensing Shape Measurements z > 2 Damped Lyman man Limit Absorption at z = 2 man Limit Systems at z < 2 pe Ia Supernovae as Cosmological Probes: Evolution and Dispersion in the Ultraviolet Spectra III rning Out the Light: A WFC3 Program to Image Tu

AR Simulations of COS Intergalactic H I and Metal Absorbers AR Mitigating Image Persistence in WFC3 NIR Observations to Allow We AR The Galaxy Major Merger Rate at z > 3: Constraints on Evolution and the LCDM Paradigm AR A Statistical Survey of Ly AR Where Do Black Holes Get Their Kicks? AR Shapelets Analysis of the COSMOS Field AR Shock Destruction of Dust in Supernova Remnants AR AR Simulated HST Observations of Elliptical Galaxies in Formation The Faint-end Slope of the Rest-frame Optical Luminosity Function at z ~ 2–3 GO Probing the Outer Regions of M31 with QSO Absorption Lines GO A Quasar Light Echo in the Local Universe? GO the Distribution of Gas and Galaxies Using Three Closely Spaced Background QSOs Tracing GO Direct Observations of Dark Matter from a Second Bullet: The Spectacular Abell 2744 GO Dynamical Hypermassive Black Hole Masses GO The Cosmological Impact of AGN Outflows: Measuring Absolute Abundances and Kinetic Luminosities GO GO the Utility of Ty Verifying Physical Characteristics of the Massive Outflow in 3C 48 GO Spiderwebs and Flies: Observing Massive Galaxy Formation In Action GO The LMC as a QSO Absorption Line System GO The Nature of Low-ionization BAL QSOs GO GO Stretching the Diversity of Cosmic Explosions: The Supernovae Gamma-ray Bursts GO The Structure and Dynamics of Virgo's Multi-phase Intracluster Medium GO Physical Properties of Quasar Outflows: From BALs to Mini-BALs GO A Deep ACS Study of the Spiral Outflow from Extreme Carbon Sta r, GO Unraveling the Mysterious Origin of GRB 070125 GO Spectroscopy of IR-selected Galaxy Clusters at 1 < z 1.5 GO High-resolution Imaging of Three New UV-bright Lensed Arcs GO A Timeline for Early-type Galaxy Formation: Mapping the Evolution of Star Formation, Globular Clusters, Dust, and Black Holes GO Calibration of Surface Brightness Fluctuations for WFC3/IR GO Mapping the Interaction between High-redshift Galaxies and Intergalactic Environment GO The Hosts of High-redshift Gamma-ray Bursts GO Narrowing in on the Hubble Constant and Dark Energy GO A Search for Ultraviolet Emission Filaments in Cool Core Clusters GO Cl0016+1609: The First (and the Last) Massive Cluster of Galaxies at z > 0.5 GO Survey SAINTS—Supernova 1987A INTensive GO ESO 137–001 in A3627 Intracluster Star Formation and Galaxy Transformation: GO WFC3 Spectroscopy of an X-ray Luminous Galaxy Cluster at z > 2 GO The Spatial Distribution of Radiation in the Complex ISM Distant Ultraluminous Galaxies GO The Origins of Short Gamma-ray Bursts SNAP A WFC3 Grism Survey for Ly Type Type Title rwick University of Pittsburgh University of Alabama University of Durham University of Arizona Jet Propulsion Laboratory University of Michigan Rochester Institute of Technology Rochester Institute of Technology Virginia Tech Virginia Tech Rutgers, the State University of New Jersey The Pennsylvania State University GO Microlensing of the Broad Line Region in Most Anomalous Lensed Quasar Arizona State University California Institute of Technology University of Hawaii Sterrewacht Leiden University of Notre Dame University of Notre Dame Smithsonian Institution Astrophysical Observatory The Pennsylvania State University AR Constraining the Co-evolution of Black Hole Growth and Star Formation at Lowest Levels Galactic Nuclear Activity University of Oklahoma Norman Campus Liverpool John Moores University GO WPVS 007: The Little AGN that Could University of Michigan University of Colorado at Boulder University of California – Los Angeles Jet Propulsion Laboratory California Institute of Technology California Institute of Technology University of California – Davis Fermi National Accelerator Laboratory University of Arizona Dominion Astrophysical Observatory University of California – Santa Cruz California Institute of Technology California Institute of Technology The University of Wa The Johns Hopkins University Space Telescope Science Institute Space Telescope University of Hawaii Harvard University CNRS, Institut d'Astrophysique de Paris SNAP Galaxy-scale Strong Lenses from the CFHTLS Survey University of California – Santa Barbara Michigan State University GO Photometric Redshift and Mass to Light Decomposition of a Double Einstein Ring The "Jackpot" in Technicolor: Commissariat a l'Energie Atomique National Optical Astronomy Observatories California Institute of Technology GO Formation and Evolution of Massive Galaxies in the Richest Environments at 1.5 < z 2.0 Space Telescope Science Institute Space Telescope Institution Cycle 17: Approved Observing Programs rnshek Nahum Arav David Tu William Keel Neil Crighton Romeel Dave Jason Rhodes Anca Constantin Renato Dupke Dan Batcheldor John O'Meara Charles Keeton Russell Ryan Richard Ellis Alan Stockton George Miley Nicolas Lehner Gabriela Canalizo J. Howk University of California – Riverside Andrew Robinson Rochester Institute of Technology John O'Meara Frederick Hamann University of Florida Karen Leighly David Bersier Mary Putman Galactic Programs Robert Kirshner J. Shull Mark Morris Joel Berge S. Cenko S. Stanford Sahar Allam Ann Zabludoff Danilo Marchesini John Blakeslee University Yale Patrik Jonsson David Law Andrew Levan Adam Riess William Sparks Harald Ebeling Andrew Fruchter Raphael Gavazzi Ming Sun Tommaso Treu Treu Tommaso Emanuele Daddi Andrew Blain Mark Brodwin Name

10 Cycle 17: Approved Observing Programs s rzan 5J ver a Large Dynamic Rang e f 0901 - rs with Archived FUV Observations GC 6440B and Te N Westerlund 1 Westerlund locity Profiles o ations of St a y Cluste r, l V407 Vu m s HST Science ung Milky Wa Yo pe Ia Supernova ray Binaries as Lighthouses - B Stars - compact Bina ry - pe Ia Environment s peak Species for AGB Jets with STIS pe Ia Supernova - - Ty type Brown Dwarf Binaries and the Prototype Y Dwar - of Isolated Neutron Star s irradiated Molecular Ga - e y: Orbits for the Leo I and II Dwarf Galaxies (Archival Studies of Leo I) explosion View of the Progenitors Core-collapse Supernovae - in of SN 1987A before Explosion Nebulae from SNAPshots of Resolved Companions Tw

III supernova Circumstellar Environment - resolved Spectroscopy of PSR B0656+14 - ung Planetary Nebulae Grow: "The Movie" Nebulae, Globular Clusters, and Binary Mergers ray Absorption and Emission Line Spectroscopy of the Galactic Corona - UV Phase - atching Yo oward a Better Understanding of ISM Turbulence through the Study of Ve oward a Better Understanding of ISM Turbulence T Beyond the Classical Paradigm of Stellar Winds: Investigating Clumping, Rotation, and The Weak Wind Problem in SMC O Star Beyond the Classical Paradigm of Stellar Winds: Investigating Clumping, Rotation, and The Weak Eclipsing Binaries in the Local Group: III—Unprecedented Accuracy Distance Determination to M33 and Calibration of Cosmic Distance Scale W AR Advancing Spectroscopy of Hot Star s AR The Mass of the Milky Wa AR Clusters in Merging Galaxies Dynamical Evolution of Young AR Determining the Phase of Carbon in Interstellar Mediu AR Spectral Models of Singly Ionized Iron AR GO The Light Echoes around V838 Monocerotis GO A Closeup View of a GO Optical and Ultraviolet Photomet ry GO FUV/X GO GO Multiple Stellar Generations in the Unique Globular Clusters NGC 6388 and 6441 GO Determining the Sub-stellar IMF in Most Massive Cosmo-chronometry and Elemental Abundance Distribution of the Ancient Star HE 152 3 GO GO The Stellar Origins of Supernova Definitive ISM Abundances through Low-mass X GO Planeta ry GO GO The Nearest Cold Interstellar Cloud GO Resolving the Smallest Galaxies with ACS GO UV Studies of a Core Collapse Supernova GO GO Eta Carinae's Continuing Instability and Recovery—The 2009 Even t GO Stellar Forensics: A Post GO Imaging the Distribution of Iron in a Ty GO Searching for Pulsations from a Helium White Dwarf Companion to Millisecond Pulsar GO Imaging the Crab Nebula-Like Supernova Remnant 3C 58 GO Resolving the Puzzling Nature of Ultra GO Probing the Interior of SN1006 GO Detecting Isolated Black Holes through Astrometric Microlensin g GO Chilly Pairs: A Search for the Latest GO Detailed Analysis of Carbon Atmosphere White Dwarfs GO The Distance Dependence of the Interstellar N/O Abundance Ratio: A Gould Belt Influence? GO Supermassive Neutron Stars or Odd Binaries: Searching for Companions to Pulsars GO GO Catching Accreting WDs Moving into Their Instability Strip(s) GO SDSS J1507: The First Halo CV or the Born with a Brown Dwarf Donor? GO Far GO Probing the Ollimation of Pristine Pos t GO GO UV Spectroscopy of the Hot Bare Stellar Core H1504+65 On the Evolutionary Status of Extremely Hot Helium Stars—Are the O(He) Stars Successors R CrB Stars? SNAP A Calibration Database for Stellar Models of Asymptotic Giant Branch Stars SNAP A SNAPSHOT Survey of the Local Interstellar Medium: New NUV Obse rv SNAP Distances of Planeta ry SNAP Snapshot Survey for Planetary Nebulae in Local Group Globular Cluster s SNAP Boron Abundances in Rapidly Rotating Earl y Type Type Title

k k xas at Austin xas at Austin xas at Austin ingen, Institut für Astronomie & Astrophysi ingen, Institut für Astronomie & Astrophysi b b Tu Tu illanova University irginia Polytechnic and State University Space Telescope Science Institute Space Telescope University of California – Berkeley University of Pittsburgh Massachusetts Institute of Technology Massachusetts Institute of Technology Massachusetts Institute of Technology University of Te NASA Goddard Space Flight Center University of Maryland Northwestern University University of California – Los Angeles Harvard University Drexel University University of Minnesota – Twin Cities University of Minnesota – Twin V Rutgers, the State University of New Jersey GO Observing the IR Catastrophe in a Deflagration Ty University of Te Whitman College Dartmouth College University of California – Santa Barbara Dartmouth College University of Te Katholieke Universiteit Nijmegen The Pennsylvania State University Science Institute Space Telescope Middlebury College Space Telescope Science Institute Space Telescope Massachusetts Institute of Technology V University of Arizona Princeton University Northwestern University Columbia University in the City of New York Columbia University in the City of New York GO Light Echoes as Probes of Supernova University of Georgia Research Foundation, Inc. AR Accurate Photodissociation of UV University of Washington University of Washington Space Telescope Science Institute Space Telescope Universitat Universitat University of Washington University of Washington University of Southampton The Pennsylvania State University Institution Cycle 17: Approved Observing Programs ne r Lanz ry Winkler angsen Yao angsen Yao Name Howard Bond Nathan Smith D. Hillier David Kaplan Y Anna Frebel Morten Andersen California Institute of Technology Giampaolo Piotto Università di Padova Adam Jensen Schuyler Van Dyk Schuyler Van Jet Propulsion Laboratory Orsola De Marco Thier American Museum of Natural History Letizia Stanghellini National Optical Astronomy Observatories SNAP The Population of Compact Planetary Nebulae in the Galactic Disk David Meyer Klaus We Kristin Chiboucas R. Rich University of Hawaii Julianne Dalcanton University of Washington Robert Kirshner Enrico Vesperini Kris Davidson Edward Guinan Saurabh Jha Justyn Maund Ulysses Sofia Robert Fesen Lars Bildsten Robert Fesen Seth Redfiel Gijs Nelemans Richard Wade Richard Wade Howard Bond Carmen Sánchez Contreras Instituto de Estructura la Materia Kailash Sahu P. Adam Burgasser Manuel Bautista Patrick Dufour Edward Jenkins Gloria Koenigsberger Universidad Nacional Autonoma de Mexico GO Shaping the Pr e David Meyer Arlin Crotts Phillip Stancil Bruce Balick Marten van Kerkwijk University of Toronto Charles Proffitt Paula Szkody Christian Knigge George Pavlov Thomas Rauch

11 Cycle 17: Approved Observing Programs s XII Absorption Systems s , and Si X ? ry VIII , Mg Legacy HST ic Halo Stars at z > 3 kp c Hubbl e s Loss s he Local Group s II Region s II Distance Scale u star s s < 1.3 with a Blind Survey for O VI , Ne Low Mass Evolutionary Models wit h Low-mass, Population II Star s ry ry ungest Star-forming Environment ansient Search st of Ve ansitio n Tr HST /COS Confirmation of Real-time Evolution and Upper Atmospheric Heating in Polari

ung Brown Dwarfs lf-Rayet Progenitors and Comparison with Red Supergiants (SN II Progenitors) in the Giant ScI Spiral M101 ~ 7–10 in the Reionization Epoch: Luminosity Functions to <0.2L* from Deep IR Imaging of HUDF and HUDF05 Fields ung? Measuring Its White Dwarf Cooling Age and Completing a m-Hot Intergalactic Gas at 0.5 < z HST /FGS Parallax for the Hyade s z r esting the Origin(s) of Highly Ionized High-velocity Clouds: A Survey of Galac t ransition Region and Chromospheric Activity on Low Metallicity Arcturus Moving Group "Alien" Dwa rf T T

AR AR Curating and Cataloging the Carina Nebula Mosaic Compact Binaries in the Core-collapsed Globular Cluster NGC 6397 AR Intermediate-mass Black Holes in Globular Clusters AR Ironing Out the Wrinkles AR A Definitive AR DRAFTS A Deep Rapid Archival Flare Tr AR The Dynamical Legacy of Star Formation in the Orion Nebula Cluster AR Internal Kinematics of the Orion Nebula Cluster GO GO Galaxies at Proper Motion Survey of Classical and SDSS Local Group Dwarf Galaxie GO GO The Ages of Globular Clusters and the Population GO The Disks, Accretion, and Outflows (DAO) of T Ta Probing Wa GO EG and ?: Providing the Missing Link Required for Modelling Red Giant Ma s GO Yo Is 47 Tuc GO Mysteries of the North Star: GO A Search for Pulsation in Yo GO GO Dynamics of the Galactic Bulge/Ba r In Search of SNIb/Ic Wo GO GO A Precision White Dwarf Cooling Age for NGC 6397 GO Searching for the Bottom of Initial Mass Functio n The First Proper Motion Measurement for M31: Dynamics and Mass of t GO GO Searching for the Upper Mass Limit in NGC 3603, Nearest Giant H GO GO The Main Sequence Luminosity Function of Low-mass Globular Clusters GO Dynamical Masses of the Coolest Brown Dwarf s Shedding Light on the New Class of Luminous Red Transient In Search of the Lost Remnant M31 RV: GO Direct Age Determination of the Local Group dE Galaxies NGC 147 and 185 GO The Formation Mechanisms of Extreme Horizontal Branch Star GO GO Photometric Metallicity Calibration with WFC3 Specialty Filters Hypervelocity Stars as Unique Probes of the Galactic Center and Outer Halo GO GO NGC 6266: The Smoking Gun of Intermediate-mass Black Holes in Galactic Globular Clusters? and the Yo WFC3 Observations of VeLLOs GO Clusters at the Galactic Center Kinematic Reconstruction of the Origin and IMF Massive Young GO Exploring the Bottom End of White Dwarf Cooling Sequence in Open Cluster NGC 681 9 GO Hunting For Optical Companions to Binary MSPS In Globular Cluster s GO Obtaining the Missing Links in Te GO GO Exceptional Galactic Halo Globular Clusters and the Second Parameter SNAP A Search for Astrometric Companions to Ve SNAP Binary Brown Bwarfs and the L/T SNAP SNAPing Coronal Iron Type Type Title

illanova University ale University New Jersey Institute of Technology New Jersey Institute of Technology Dartmouth College University of Massachusetts Space Telescope Science Institute Space Telescope College University of Dublin, Trinity University of British Columbia V Northwestern University California Institute of Technology Universiteit Leiden American Museum of Natural History University of California – Los Angeles The Pennsylvania State University University of Colorado at Boulder University of Colorado at Boulder at Austin University of Texas Lowell Observatory University of California – Santa Cruz University of Hawaii Science Institute Space Telescope University of Maryland Max-Planck-Institut für extraterrestrische Physik Y GO Globular Cluster Candidates for Hosting a Central Black Hol e Max-Planck-Institut für Astronomie, Heidelberg GO An HST /STIS Spectroscopic Investigation: Is Kelu-1 AB a Brown-Dwarf–Brown-Dwarf Bina Space Telescope Science Institute Space Telescope New Mexico State University University of Michigan Georgia State University Research Foundation Science Institute Space Telescope University of Maryland GO Follow-up Investigation on a Possible Third Member of the Sirius Sytem University of California - Los Angeles California Institute of Technology California Institute of Technology Columbia University in the City of New York Science Institute Space Telescope Science Institute Space Telescope GO Stars in M3 1 A Deep Exploration of Classes Long-period Variable The Johns Hopkins University Lowell Observatory Dartmouth College University of Notre Dame Institution Cycle 17: Approved Observing Programs odd Tripp odd Tripp racy Huard ravis Barman Name Garth Illingworth Slawomir Piatek University of California – Santa Cruz Brian Chaboyer Gregory Herczeg T California Institute of Technology Max Mutchler Jonathan Grindlay Brian Espey Large Programs Harvard University Harvey Richer Edward Guinan Stefan Umbreit Ann Marie Cody Konrad Kuijken Michael Shara Sebastien Lepine American Museum of Natural History R. Rich Kevin Luhman Roeland van der Marel Science Institute Space Telescope Alexander Brown University of Colorado at Boulder Thomas Ayres Thomas Ayres Thomas Ayres Thomas Ayres Thomas Brown George Benedict Nitya Kallivayalil Massachusetts Institute of Technology SNAP Continued Proper Motions of the Magellanic Clouds: Orbits, Internal Kinematics, and Distance Philip Massey Graeme Smith Michael Liu Howard Bond Rachel Osten Eva Noyola Marla Geha Micaela Stumpf Francesco Ferraro Università di Bologna Jon Holtzman Oleg Gnedin Sergio Dieterich Julio Chaname T Andrea Ghez Adam Kraus Arlin Crotts Luigi Bedin Iain Reid Imants Platais T Aaron Dotter Nicolas Lehner

12 Cycle 17: Approved Observing Programs rm White Dwarfs and Planets y, ung, Edge-On Debris Disk of HD32297 ans-Neptunian Binaries ransiting Planet Debris Disks around Two Wa Debris Disks around Two riations mass T - e of a Beta-Pic Analog, the Yo ansiting Exoplanet Evaporating? rtices Program: Populations, Formation Histor ey of the Kuiper Belt: A New Window into Formation Outer Solar System ung Stars via High-resolution UV Spectra pe 1a Supernovae in the SDSS Survey Go: Constraining FUV Variability in the Gaseous Inner Holes of Protoplanetary Disks Go: Constraining FUV Variability 2 High- z Galaxies with WFC3 Pure Parallel ater and Methane on a Neptun compositional Su rv ry - A Dynamical HST COS Observations of the Atmosphere and Airglow/Aurora Enceladus

AR Planetary Perturbations of Circumstellar Debris Disks AR An Archival Search for Faint Kuiper Belt Objects AR Spectroscopy for Extrasolar Planets 3D Transit AR Measuring the Size Distribution of Small Kuiper Belt Objects Using FGS GO How Far Does H GO Coronagraphic Imaging of Debris Disks Containing Gas GO Solar-type Stars Follow-up Observations of Debris Disks around Two GO Investigating Jet Rotation in Yo GO GO How Galaxies Acquire Their Gas: A Map of Multiphase Accretion and Feedback in Gaseous Galaxy Halos GO A Search for W GO Hot-Jupiter HD 189733b Characterizing Atmospheric Sodium in the Transiting GO Elucidating the Mystery of the Io Footprint Time Va GO A Comprehensive Survey of Neptune's Small Moons and Faint Rings GO Spectrum of the Exoplanet HD 189733b A Complete Optical and NIR Atmospheric Transmission GO Probing the Atomic and Molecular Invento ry GO Investigations of the Pluto System GO Mutual Orbits, Colors, Masses, and Bulk Densities of 3 Cold Classical Tr GO The Parallax of the Planet Host Star XO-3 GO Bright Galaxies at z > 7.5 with a WFC3 Pure Parallel Survey GO Infrared Survey of Star Formation across Cosmic Time GO Search for Ve GO GO Dynamics in the Atmosphere of Evaporating Planet HD 189733b GO GO Is the Atmosphere of Hottest Known Tr Physical Parameters of the Upper Atmosphere Extrasolar Planet HD 209458b GO A STIS NUV Search for Shocked Interstellar and Circumstellar Gas toward the Debris Disk System, HD 61005 GO An Intensive COS Spectroscopic Study of the Planeta ry GO of Opportunity Imaging an Unusual Cloud Feature on Uranus Target GO Propagation in the Planet-forming Region of a Circumstellar Disk Ly-alpha GO Imaging Saturn's Equinoctal Auroras GO Jovian Upheaval and Its Impact on Vo GO Investigating Post-equinox Atmospheric Changes on Uranus GO ry The WFC3 Galactic Bulge Treasu SNAP Monitoring Active Atmospheres on Uranus and Neptune SNAP The Host Environments of Ty Type Type Title rwick le University University of Michigan NASA Goddard Space Flight Center SETI Institute Jet Propulsion Laboratory California Institute of Technology California Institute of Technology Ya University of Notre Dame Harvard University CNRS, Institut d'Astrophysique de Paris Space Science Institute SETI Institute University of Arizona University of Bern Lowell Observatory University of Texas at Austin University of Texas Southwest Research Institute Lowell Observatory Space Telescope Science Institute Space Telescope University of California – Los Angeles Carnegie Institution of Washington Carnegie Institution of Washington Boston University California Institute of Technology California Institute of Technology Open University University of California – Berkeley The University of Wa Space Science Institute University of Michigan Boston University University of California – Berkeley Space Telescope Science Institute Space Telescope Institution Cycle 17: Approved Observing Programs Name Nuria Calvet John Krist Planetary & Star Formation Programs Aki Roberge Kathy Rages Peter Garnavich Francesca Bacciotti Christopher Johns-Krull Osservatorio Astrofisico di Arcetri Rice University Michael Brown Jason Tumlinson Jason Tumlinson Heather Knutson Lawrence Sromovsky University of Wisconsin – Madison Jean-Claude Gerard David Sing Université de Liege Joseph Hahn Mark Showalter David Trilling David Trilling Frederic Pont Travis Barman Travis Seth Redfield Matthew Holman Marc Buie Smithsonian Institution Astrophysical Observatory GO A Direct Glimpse into the Atmosphere of a Hot Jupiter HAT-P-1: William Grundy Program Treasury Thomas Brown Michele Trenti Michele Trenti Matthew Malkan Alain Lecavelier des Étangs Pure Parallel Programs CNRS, Institut d'Astrophysique de Paris Hao-Jing Yan John Clarke Alfred Vidal-Madjar Eran Ofek CNRS, Institut d'Astrophysique de Paris Carole Haswell Holly Maness Boris Gaensicke Heidi Hammel Thomas Bethell Jonathan Nichols Imke de Pater

13 WFPC2 Closeout

John Biretta, [email protected]

he Wide Field Planetary Camera 2 (WFPC2) has been the longest lived and most reliable science instrument onboard Hubble. During its nearly 15 years on-orbit, it has amassed 180,000 images. T For many years, it was Hubble’s primary imager at visible wavelengths, and it has resumed that role over the past 18 months when newer instruments failed. Nonetheless, it is time to make room for newer technologies and fresh detectors, and hence WFPC2 will be decommissioned and returned to earth during Service Mission 4. As the WFPC2 mission approaches its end, a broad effort has been undertaken to update, enhance, and finalize its calibrations in the following areas. Ultraviolet (UV) throughput variations Figure 1. Typical data used to deter- WFPC2 experienced cyclical variations in its UV throughput as contaminants condensed on the cold mine the WF4 CCD gain corrections Charge-Coupled Device (CCD) windows—and were later removed by periodic decontamination proce- as derived from internal flats. The dures. These variations were tracked by thousands of standard star observations extending over many vertical axis gives the ratio of WF4 years. We have now reanalyzed these data to provide a more accurate photometric calibration in the UV. counts to reference image (or true) The final product of this work will be an updated SYNPHOT contamination table for photometric calibra- counts while the horizontal axis gives tion. We will also place a new keyword, ZP CORR (zero-point correction), in the header of each image, the reference image counts. Several giving the estimated throughput loss for the image, based on the epoch and filter. fiducial WF4 CCD bias levels are high- lighted with different colors. Images Charge-transfer efficiency (CTE) with normal bias levels (311 DN in Radiation damage has slowly degraded the CTE of the CCD detectors of WFPC2 during its time red) have normal counts (WF4/refer- on-orbit. This effect reduces photometric counts for targets in a complex fashion, depending on target ence = 1), while images with low brightness, location on the detector, and background illumination. To perform a final evaluation of CTE bias (e.g., 25 DN in black) have low corrections, we made extensive observations of star clusters with various levels of background light counts. Given a WF4 bias level and from a pre-flash. We also made new observations of galaxy clusters and the Hubble Deep Field North pixel value, the corrected counts can to assess the impact of CTE on extended targets. While observers will need to manually correct CTE be easily determined. effects themselves, we added a warning message to data headers giving a rough estimate of the CTE effects, based on the epoch of the data and amount of background light in the WF4 CountsWF4 vs. Reference Counts vs. Counts Reference Counts image. CCD gain anomaly in the WF4 channel 1.0 Starting in early 2002, the gain of the WF4 CCD gradually became unstable. We devised a correction for these gain varia- tions, which is now installed in the WFPC2 0.8 calibration pipeline along with a new refer- ence file. Tests indicate the corrections are accurate to 1% to 2%. A side effect of the 0.6 gain anomaly is the appearance of faint horizontal streaks in the WF4 data, with an amplitude up to about 1 ADU. We wrote WF4 Bias Level new software to remove these streaks, 311 DN 0.4 which we will make available to users 295 DN 275 DN as “destreak” in the STSDAS software 215 DN package. This software is also capable of removing bias variations, which occasion- WF4 Counts / Reference Counts 0.2 150 DN 25 DN ally appear in the other CCDs. Photometric zeropoints We are reevaluating the zeropoints at 0.0 the end of WFPC2’s mission using new 0 1000 2000 3000 4000 observations of standard stars and stan- Reference Image Counts (per pixel) dard fields. We will update the SYNPHOT filter throughput tables and detector effi- ciency tables as needed. 14 Flat fields for broad-band filters Introducing John We reevaluated the accuracy of the flat fields for broad-band filters by a new technique: using the Mather to the Science Earth illuminated by the full Moon as a diffuse light source. We found the existing flats to be quite Operations Center accurate, and plan no further updates to the flat fields. Filter red leaks We measured the leak component directly for the first time on-orbit by crossing the UV and blue filters with other filters and observing a bright standard star. We will use the results to update SYNPHOT throughput tables. Narrow-band filters We made and analyzed new observations to assess the wavelength and photometric stability of narrow-band filters over the 15-year WFPC2 mission. We will update the SYNPHOT throughput tables as needed. Linear ramp filters We made a new series of photometric calibrations that will produce substantially more accurate photometry in many wavelength ranges. We will incorporate the results in new SYNPHOT tables, with improved photometry keywords appearing in the data headers. Polarizers We made new observations to fully reevaluate the calibrations of the polarizers near the mission end. The analysis of these data is pending. Geometric distortion and astrometry We reevaluated distortion corrections, and generated new, time- dependent corrections for the offsets between the four CCD chips over the entire WFPC2 mission. We addressed the 34-row effect, where due to a manufacturing error, every 34th pixel row of the CCD is about 3% too narrow. These resulted in new geometry tables—IDCTAB, OFFTAB, and DGEOFILE—used for “drizzling” data onto a corrected grid. In addition, we Figure 2. Image of spiral galaxy NGC 4736 taken on the WF4 CCD in May 2005 before (top) and after (bottom) applying the added a new keyword, VAFACTOR, to the header of each image, which new “destreak” software. describes the small effect of the velocity aberration due to Hubble’s orbital motion. Mosaic image product We added a new image product to the pipeline output, which geometrically corrects and aligns the four CCDs into a single image covering the entire WFPC2 field-of-view. It is generated by automatically running the Dr i z z l e software on each image, using the newest geometric corrections. The result will be stored in the archive, along with the various data products already available. The new product, which will be available for all WFPC2 images, serves primarily as a quick-look image. It will be fully calibrated, but will not be corrected for cosmic ray hits. Bias and dark calibrations We generated new super-bias and super-dark reference files for the last few years of the WFPC2 mission, which will be used by the pipeline calibration software. We are also studying the long-term history of both the bias and dark calibrations. As the various calibrations are finalized, we will migrate the WFPC2 data to a static archive. Currently, WFPC2 data are calibrated on-the-fly at the time users request the data from the Hubble archive, thus providing the most up-to-date calibrations. Once the calibration files and software are finalized, however, this dynamic approach will no longer be necessary. The WFPC2 calibration pipeline will be run one last time for each image, and the results will be stored in a static archive—in both the waiver FITS format traditionally used by WFPC2, and in the standard multi-extension FITS format used by newer instruments. Subsequently, the static archive will fulfill requests for the final calibrated images, which will speed fulfillment and reduce operating costs. The transition to the static archive will occur gradually in late 2008, and be completely transparent to archive users. Both the raw data and calibration reference files will continue to be available in the archive, should users wish to perform their own calibrations. We will revise and update WFPC2 documentation, including a final version of the WFPC2 Instrument Handbook in early fall 2008 and the WFPC2 Data Handbook in spring 2009. Many shorter reports will be produced as calibrations are updated and finalized. Such documents are always available at http:// www.stsci.edu/hst/wfpc2. W

15 NICMOS Update: Legacy Recalibration/Reprocessing Anton M. Koekemoer, [email protected]

he Near-Infrared Camera and Multi-Object Spectrometer (NICMOS), which was installed in 1997 during Servicing Mission 2 to the Hubble Space Telescope, has played a pioneering role as the T first space-based instrument capable of observing with high spatial resolution in the near-infrared wavelength range. As such, it has an enormous scientific legacy, with more than 77,000 datasets accumulated in the Hubble archive, along with many unique scientific discoveries published to date. Nevertheless, its infrared detectors, constructed using HgCdTe technology, are susceptible to a range of instrumental effects, which produce much more prominent artifacts in NICMOS data than in CCD data from other instruments. While many of these effects can be essentially corrected, substantial residuals often remain that can limit the scientific value of the data. Given the extensive NICMOS data now archived, including the results of an enhanced calibration observing program during the past two cycles, the Institute’s NICMOS instrument team has begun to elevate the calibration of the instrument to levels significantly above the standard defaults. In addition to now offering the potential for higher scientific quality of the data, this effort also helps lay a foundation for the next generation of infrared instruments, including the infrared channel of Wide Field Camera 3 and the James Webb Space Telescope. These improved calibration techniques will be useful for the new instruments, and the refined NICMOS scientific products will help define new scientific programs and calibration observations with the future instruments. Behind the variety of instrumental artifacts in NICMOS data, the dominant underlying physical causes are temperature variations and persistence effects. The sensitivity and dark-current characteristics of the detectors are functions of temperature, with noticeable variations in the data from temperature changes as small as a few tenths of a degree. In addition, even after several orbits, persistent signals from bright sources, cosmic rays, and even the bright Earth can remain apparent in the data. Other low-level, residual effects include detectable glow from the amplifiers at the corners of the detectors during readout; electronic cross-talk in all four detector quadrants when a bright source is present in one quadrant; and time-varying bias levels, which introduce relative offsets between quadrants and electronic “shading” bands across images. The team has now recalibrated all dark frames and flat-field exposures obtained since the installation of NICMOS. This process employed the recently developed “temperature-from-bias” algorithm, which uses the detectors’ bias levels to provide a much more accurate reading of the temperature than the measurements available from the mounting-cup sensors. We are also using the new algorithm to obtain a more accurate measurement of the detector temperature during science exposures, thereby enabling each exposure to be recalibrated using the dark frames and flat-field files that are best matched to the detectors’ actual temperature during each exposure. This process substantially improves the correction of many low-level, residual, systematic effects, including dark-current structure, amplifier glow, and flat-field residuals. Any remaining residuals can be removed iteratively by using Multidrizzle to combine the images and create a source-free background image, which can be transformed back to each original exposure, used to create a median background map, and can then be subtracted from the input exposures. We have made a number of significant improvements to the c a l n i c a software, which is used to calibrate exposures and reject cosmic rays. These improvements include more accurate error maps, updated algorithms for identifying and rejecting cosmic rays and bad pixels, and improved fitting of the count-rates measured during each read-out (referred to as “up-the-ramp” fitting). The new c a l n i c a software is now included in the OPUS pipeline for reprocessing all NICMOS data. Other new NICMOS software in the OPUS pipeline includes routines for removing low-level persistence from the bright Earth and cosmic rays encountered in passages through the South Atlantic Anomaly, and for using the more accurate measurement of the temperature from the bias levels. These processing enhancements, together with the improvements in instrument calibration, are resulting in a final set of reprocessed “legacy” NICMOS data with substantially enhanced scientific value—an appropriate contribution to the future of Hubble infrared science. For any questions about NICMOS or further information on the improvements in calibration and reprocessing, along with the status of the final reprocessed archive, please visit the NICMOS web page (http://www.stsci.edu/hst/nicmos/) and the bulletin board (http://forums.stsci.edu/phpbb/ viewforum.php?f=13), or send an email message to [email protected]. W Acknowledgements to the rest of the NICMOS Team and support personnel, including Elizabeth Barker, Eddie Bergeron, Tomas Dahlen, Ilana Dashevsky, Roelof de Jong, Dave Grumm, Robert Jedrzejewski, Vicki Laidler, Chris Long, Nor Pirzkal, Adam Riess, Denise Smith, Deepashri Thatte, Alex Viana, Tom Wheeler, and Tommy Wiklind.

16 Webb Confirmed for Implementation Mark Clampin, Mark.Clampin@nasa.gov and Peter Stockman, [email protected]

n July 10, 2008, NASA confirmed the James Webb Space Telescope, marking the project’s formal transition from the formulation phase to the implementation phase. Confirmation Oinitiates monitoring of the project by Congress. NASA’s decision followed two intensive reviews of the Webb project, the Preliminary Design Review (PDR) in March, and, several weeks later, a second Non-Advocate Review (NAR). The first NAR, dealing specifically with Webb’s new technologies, was held in January 2007. The Webb design evolved considerably in the run-up to the PDR, as illustrated in the figure below. While the telescope optics and their deployment structures remain the same, the sunshield size and shape have been optimized. For protection during launch, the sunshield will now be stowed on two folding pallets. After launch, booms will extend the sunshield from the pallets. Located at the rear of the sunshield, to neutralize the generated solar-radiation torque, a trim tab will help manage the momentum in the spacecraft’s reaction wheels. The design of the spacecraft bus—which provides support functions, such as avionics, power, and computers—has also evolved, due to the decision to employ a single, long solar array. The next 12 months will present exciting challenges for the Webb project. Before their final cryo- polishing, the first mirrors intended for flight will be delivered to the Marshall Space Flight Center for testing. The last of the science instruments will complete their Critical Design Reviews (CDRs), and the fabrication of the flight instruments will begin. The CDR for the entire Webb mission should take place in 2009. The project schedule shows readiness for launch in mid 2013, when an Ariane 5 rocket will lift the Webb observatory into space from the European Space Agency spaceport at Kourou, French Guiana. Science operations—the fun part!—will begin after instrument checkout and the cruise to Webb’s station at L2, the second Earth-Sun Lagrange point. W

Current Webb design Upper right: The design uses a long, single solar array in a “tail-dragger” configuration. Lower right: The sunshield includes a trim tab to balance the radiation torque. Lower left: The sunshield is stowed on two folding pallets, which remain with the observatory after deployment. Upper left: The optimized sunshield has straight edges; the deployable optics are unchanged.

17 Status of the Webb Science Operations Center

Peter Stockman, [email protected]

he Institute’s Webb Science and Operations Center (S&OC) has begun developing the software systems to operate the observatory. The design and implementation of the systems to process proposals and plan T observations are the long-lead items with highest priority. The corresponding systems for Hubble are the Phase 1 and Phase 2 proposal systems, and the long- and short-range planning system, which prioritize and manage the observations on approximately monthly and weekly intervals, respectively. The development team plans to re-use many features of the Hubble Astronomer’s Proposal Tool (APT) and some features of the Spitzer Science Center’s Sp o t proposal tools. In particular, the Webb proposals will use observation templates rather than configuration lines. This is possible because Webb observations need not be crafted to fit into 96-minute orbits, and can extend for days without interruption. Astronomers will find using the Webb templates much simpler than preparing Phase 2 proposals for Hubble. As a result, the SOC will encourage proposers to submit completed proposals for those observations not requiring special timing or orientation constraints. For more complicated programs, or those that have special orientation limitations, the observers will submit the complete observation data using the same tools as for the initial submission. Like Hubble, Webb will use a portion of its imaging field for a fine guidance camera to fix and stabilize all observations. (This camera will be provided by the Canadian Space Agency.) Hubble’s Guide Star Selection System and Guide Star Catalog II will provide many of the software and database systems needed to find and select guide stars for Webb observations. We are considering adding faint stars from the Sloan Digital Sky Survey, 2MASS, and other surveys to fill in portions of the sky near the north galactic pole and in densely populated or dust-obscured

regions. The Webb fine guidance camera uses HgCdTe detectors and can guide on JAB ~ 19 stars. The long-range planning software for Webb will use a version of the Sp i k e optimization and constraint-checking program used for Hubble and other observatories. For Webb, the most important constraints are the annular field of regard (similar to that for Spitzer), the minimization and balancing of radiation torques, guide star availability, and any special orientation or timing observation constraints. The short-term scheduler must also take these factors into account, but it has the flexibility of ordering the observations to minimize the effects of radiation torques, improve observing efficiency, and manage daily data volumes. In January 2008, the development team passed the System Requirements Review and has begun adapting and modifying Hubble code. In early February, we received approval from NASA HQ to add the tracking of solar system targets to the Webb and SOC development efforts. Targets may have apparent linear motions up to 30 milliarcsec per second of time. This will be sufficient to track targets at the distance of Jupiter and beyond. Brief, narrowband observations of Mars should be possible near quadrature. Because the Webb detectors are optimized for long exposures on faint sources, the “warmer” resolved planets (Jupiter, Saturn) can saturate the near- and mid-infrared detectors within a readout period for imaging through many filters and for low-resolution spectroscopy (http://www.stsci. edu/jwst/externaldocs/technicalreports/JWST-STScI-001375.pdf). Higher spectral-resolution imaging and spectroscopy of these objects should be possible. Observations of Neptune, Uranus, their satellites, minor planets, and Kuiper Belt Objects will be straightforward. We anticipate that the data needed to plan Solar System observations will be provided by the system used for Hubble. More information on the Webb telescope can be found at: http://www.stsci.edu/jwst/. Specific Webb-related questions can be addressed to [email protected]. W

National Virtual Observatory

Bob Hanisch, [email protected]

he goal of the National Virtual Observatory (NVO) project is to make it possible for astronomical researchers to find, retrieve, and analyze astronomical data from ground- and space-based telescopes T worldwide. The origins of the NVO can be traced to the establishment in the early 1990s of wavelength-oriented science archive centers for NASA mission datasets. These were the first comprehensive astronomy archive

18 facilities having a close connection between data and expertise in calibrating and using the data. Also during the 1990s, several large-scale digital sky surveys were begun, most notably the Sloan and 2MASS surveys. The images and source catalogs derived from these surveys demonstrated the value of homogeneous, on-line datasets. In April 1999, the concept for a “national virtual observatory” arose at a meeting of the Decadal Survey Panel on Theory, Computation, and Data Discovery. In September 2001, the National Science Foundation’s (NSF’s) Information Technology Research program awarded $10M to a 17-organization collaboration led by Alex Szalay (Johns Hopkins University; JHU) and Paul Messina (Caltech) to build the infrastructure for the NVO. Since that time, the Institute has been a key member of the NVO development team. The NVO enables a new way of doing astronomy. It facilitates the move from an era of observations of small, carefully selected samples of objects in one or a few wavelength bands, to the use of multi-wavelength data for millions, if not billions, of objects. Such datasets allow researchers to discover subtle but significant patterns in statistically rich and unbiased databases, and to understand complex astrophysical systems by comparing data with numerical simulations. To enable such qualitative advances, NVO provides simultaneous access to multi-wavelength archives and tools for advanced visualization and statistical analysis. The development phase of the National Virtual Observatory is coming to a close in the next few months. Over the past 6½ years we have established the underlying technologies that will allow us to realize the scientific goals of the project. Working in collaboration with partners in the International Virtual Observatory Alliance (IVOA), we have developed standards for describing data and data collections, for accessing images, spectra, catalogs, and databases in a uniform manner, and for describing the sky coverage and intersections of astronomical archives. We have most recently been finalizing a new, user-friendly data-discovery web site, where astronomers can use a set of web-based applications that work together to provide easy access to images and catalogs. Users of the Hubble Legacy Archive will find a familiar interface, as we utilize the same table browser. This makes it easy for users to rearrange columns, change the sort order, and apply filters to select table subsets. As part of the faculty of the NVO Summer Schools, Institute staff members help train graduate students, postdocs, research astronomers, and professional programmers. The fourth Summer School is scheduled for September 3–11, 2008, in Santa Fe, New Mexico, with 50 participants. A number of Institute staff members attended previous Summer Schools, and they are now exploiting virtual observatory capabilities in their research and development efforts. One outcome of the Summer Schools is a book—The National Virtual Observatory: Tools and Techniques for Astronomical Research—published as part of the Astronomical Society of the Pacific Conference Series (Vol. 382). This book provides a comprehensive view of how the virtual observatory works and how to use it as a scientist and/or programmer. It is available as an open-access publication at http://aspbooks.org/a/volumes/table_of_contents/?book_id=420, and in traditional paper form at http://www.astrosociety.org/CS382.html. This fall, during the week of October 26–31, 2008, the Institute and JHU will be co-hosting the semi-annual IVOA Interoperability Meeting. The “Interop” is the venue where virtual observatory developers from the international projects get together to work out technical details about standards and protocols, share experiences with implementations, and plan and prioritize work for the coming year. We expect to have about 100 participants from 15 countries. The Institute partnered with eight other organizations—National Optical Astronomy Observatory, National Radio Astronomy Observatory, Smithsonian Astronomical Observatory, Infrared Processing and Analysis Center, California Institute of Technology, JHU, High Energy Astrophysics Science Archive Research Center, and National Center for Supercomputing Applications—to submit a proposal in April to NSF for the operations phase of the virtual observatory, now called the Virtual Astronomical Observatory. The proposal was formally submitted from the VAO, LLC, a new corporation jointly sponsored by Association of Universities for Research in Astronomy and Associated Universities, Inc. The VAO will be co-funded by NASA (25%) and NSF (75%). W

For more information about NVO and an introduction to our web-based research tools, please visit the NVO website at http://www.us-vo.org/.

19 Hubble Fellow Program News Ron Allen, [email protected]

he Hubble Fellowship Program supports outstanding postdoctoral scientists whose research is related to the scientific mission of the Hubble Space Telescope. The research may be T theoretical, observational, or instrumental. This program is funded by NASA and is open to applicants of any nationality. The fellowships are tenable at U.S. host institutions of the fellows’ choice, subject to a maximum of one new fellow per host institution per year. The duration of the fellowship is up to three years. Hubble Fellows Symposium Each year, the Hubble Fellows present the results of their research at a symposium at the Institute, which this year was held March 10–12, 2008. The talks were given in the recently dedicated John N. Bahcall Auditorium. We enjoyed presentations from all but one of the current total of 27 Hubble Fellows; Jenny Greene (HF ’06; Princeton) had a conflict with an observing run. The program and recorded video of the symposium are available at http://www.stsci.edu/ institute/conference/archive.html/. The Hubble Fellows Symposia are unique in that they include the latest research not from just one field, but from all fields in astronomy. They are an excellent opportunity to hear about the latest “hot” topics and to talk with young experts working on them. Attendance is open to all in the professional astronomical community.

Participants in the 2008 Hubble Fellows Symposium, including fellows who were appointed in 2005, 2006, and 2007.

20 2008 Hubble Fellows 2008 Hubble Fellow PhD Institution Host Institution

Kevin A. Bundy Caltech 2006 UC Berkeley Julio Chanamé Ohio State 2005 Carnegie DTM Richard Cool U. Arizona 2008 Princeton Elena Gallo U. Amsterdam 2005 MIT Suvi Gezari Columbia 2005 JHU Brandon C. Kelly U. Arizona 2008 SAO David R. Law Caltech 2008 UCLA Andrei Mesinger Columbia 2006 Princeton Naveen Reddy Caltech 2006 NOAO Emily L. Schaller Caltech 2008 U. Hawaii Louis E. Strigari Ohio State 2005 Stanford Jong-Hak Woo Yale 2005 UCLA

Selection of the Hubble Fellows The 2008 Hubble Fellow Selection Committee met at the Institute on January 3–4 to consider the 208 applications that were received by the deadline of November 8, 2007. The 11-member committee, under the able chairmanship of Prof. Frank Shu (University of California, San Diego), accomplished the formidable task of defining the ranked short list for the 12 available fellowships. Offers were made, and by mid-February the list of 2008 Hubble Fellows was complete. They will be taking up the new fellowships in the fall of 2008. Changes to the Hubble Fellow Program NASA Headquarters is making make several changes to the Hubble Fellow Program, which will be announced separately. In broad outline, NASA will generalize the Hubble Fellows Program to include the scientific goals addressed not only by Hubble, but by any of the missions in NASA’s Cosmic Origins Program. These missions presently include: the Hubble Space Telescope, Spitzer Space Telescope, Stratospheric Observatory for Infrared Astronomy, the Herschel Space Observatory, and the James Webb Space Telescope. No major changes are anticipated in the conduct of the Hubble Fellow Program by the Institute, since the selection criteria will remain largely as they are now. It is possible that the number of Hubble Fellowships to be awarded will increase. W

Galaxy Silhouettes NASA’s Hubble Space Telescope has captured a rare alignment between two spiral galaxies. The outer rim of a small, foreground galaxy is silhouetted in front of a larger background galaxy. Skeletal tentacles of dust can be seen extending beyond the small galaxy’s disk of starlight. From ground-based telescopes, the two galaxies look like a single blob. But the Advanced Camera’s sharp “eye” distinguished the blob as two galaxies, cataloged as 2MASX J00482185-2507365. The images were taken on Sept. 19, 2006. For more information, please see: http://hubblesite.org/ newscenter/archive/releases/2008/33/

NASA, ESA, and The Hubble Heritage Team (STScI/AURA)

21 This edition of the Institute Newsletter continues to reprint science articles from NASA’s annual Hubble 200X Science Year in Review. We are pleased to continue this series with “Binaries (and More) in the Kuiper Belt,” by Keith Noll, “and “Galaxies over the Latter Half of Cosmic Time,” by Marc Davis and Sandra M. Faber, both of which appeared in “Hubble 2006.”

Binaries (and More) Keith Noll is an Astronomer at the Space Telescope in the Kuiper Belt Science Institute in Baltimore, Keith Noll, [email protected] Maryland. He is interested in that part of the universe to he Kuiper Belt is a broad ring of small planetary objects outside Neptune’s orbit, or over which his great-grandchildren 30 times Earth’s distance from the Sun. Astronomers believe that the original planet- forming disk around the young Sun extended out into this region. But here, the disk might someday travel. For would not have cleared as in the interior region, where the rubble of planet building was swept up by collisions, or cast away by gravitational perturbations as the major planets the past five years, he has Tformed. For years, the Kuiper Belt was a hypothetical entity, comprising Pluto but no other known been studying the fascinating objects. Then, starting in 1992, with the advent of a new generation of sensitive digital detectors, astronomers began looking deeper and discovering many “trans-neptunian objects” (TNOs). The and complex objects that lie number is over 1000 in 2006, the same year the International Astronomical Union redefined Pluto beyond Neptune with the as a “dwarf planet” and signified it the prototypical large TNO. Among the most intriguing and instructive TNOs are the gravitationally bound “trans-neptunian Hubble Space Telescope. binaries” (TNBs), which include an astonishingly high fraction of all TNOs. (Two TNBs are multiple systems with additional members.) The unsurpassed imaging power of the Hubble Space Telescope is playing a key role in finding, characterizing, and ultimately understanding the enigmatic TNBs. The first TNB was Pluto: its large satellite, Charon, was discovered in 1978. A true binary, the pair orbits a point—the center of mass—that lies outside both bodies. In 2006, Hubble found two smaller moons outside Charon’s orbit, making this system even more fascinatingly complex. It is remarkably well ordered: the orbits are circular and lie in a common plane. As one possible way to explain this system, astronomers speculate that Pluto was originally single, but experienced a huge collision early in the history of the Solar System. Debris from the collision was incorporated into the satellites, whose orbits gradually circularized by tidal forces and evolved to their current sizes. (This is also the leading scenario for the formation of Earth’s Moon.) This hypothetical origin, if correct, puts Pluto in the minority of known TNBs. The second TNB was 1998 WW31. The primary object was found in 1998, and its companion was first detected in 2000. Observations by Hubble helped determine the orbit, which has maximum physical separation of 44,000 km, high orbital elongation (eccentricity = 0.82), and a period of 520 days. Using basic physics, astronomers can use the measured orbit size and period to compute the total mass of 1998 WW31—one six-thousandth the mass of the Pluto/Charon system, which is too low to have circularized the orbit of the companion at the observed separation over the age of the Solar System. In 2003, astronomers used Hubble for the first unbiased search for TNBs. “Unbiased” means that the sample was selected without favoring any attribute that might be related to multiplicity, in order to ensure that the findings would be a fair estimate of the occurrence of multiplicity in the general population of TNOs. The pictures from Hubble were scanned not only for clearly resolved companions (three were found), but also for subtle distortions of the TNO images that might be caused by an unresolved companion. (This extension beyond the normal limits of a telescope’s resolution is possible because of the exceptional stability of the Hubble observatory.) In this way, six more TNBs were found, for a total of 9 out of a sample of 81 TNOs investigated. The best estimate—that about 11% of TNOs are multiple systems—is a lower limit, because the search could only have detected the subset of companions that were sufficiently bright and well separated to be found at the time of the observations. That left many beyond the range of detection, which suggests that the true fraction of multiple systems is substantially larger.

22 This is an artist’s impression of noontime on Sedna, the farthest known planetoid from the Sun. Over 8 billion miles away, the Sun is reduced to a brilliant pinpoint of light that is 100 times brighter than the full Moon. The Sun would actually be the angular size of Saturn as seen from Earth—far too small to be resolved with the human eye.

Illustration by A. Schaller

The discoveries have accumulated rapidly. As of 2006, a total of 34 TNBs are known, of which Hubble discovered 26. Mutual orbits have been determined for nine systems, eight based on Hubble observations of the separation and orientation of the components at different times. The orbits show a large diversity in diameter, eccentricity, and period. The shortest period so far is 6.4 days for the Pluto/Charon system; 2001 QT297 has the longest period, 825 days. For observers, the key constraint is angular separation. In the most widely separated system, 2001 QW322, the components appeared to be separated by 4 arc seconds at the time of discovery; the smallest detected separation has come from Hubble, about 50 milliarc seconds. (At the typical distance of a TNB, about 40 times the radius of Earth’s orbit, 1 arc second corresponds to 29,000 km.) Theoretical studies indicate no reason to suspect a lower limit to the physical separations of TNBs, and the large-amplitude, long- period brightness variations of one TNO—2001 QG298—suggests it is one of a potentially significant population (~10–20%) of binaries so close they are nearly in contact. For six of the nine systems with known orbits, the total mass has been determined with an uncertainty of 10% or better. Measured masses range from a low of six-millionths the mass of the Moon for (58534) Logos/Zoe to 0.2 lunar masses for Pluto/Charon. As further research clarifies the occurrence rate and dynamical characteristics of TNBs, and as theoretical models are developed to interpret the results, we can anticipate a profound contribution to our understanding of conditions and processes in the original protoplanetary disk. Massive collisions may have formed a few of the largest multiple systems, like Pluto and 2003 EL61.* Continued page 24 *Now known as Haumea [editor’s note]. 23 Binaries Nevertheless, the nearly equal size of components in TNBs suggests that the vast from page 23 majority cannot have formed from collisions. On the other hand, the direct, collisionless capture of a single similar-mass companion by a solo TNO is impossible under the laws of orbital mechanics. Thus, most TNBs must have formed through multibody, gravitational encounters. For either collisions or capture to have produced the number of binaries being found, a much denser environment than the current Kuiper Belt is required: an environment like that thought to exist in the disk surrounding the infant Sun. In other words, the TNBs are primordial, dating back to the first few million or tens of million years after the Sun began to form. Since then, TNBs are slowly being destroyed by rare gravitational encounters, which can also change their orbits around the Sun—but no new TNBs can have formed. We can see hints of this slow depletion in the results of the 2003 survey. Comparing two subsets of TNOs—those that have or have not been scattered out of the plane of the Kuiper Belt—the occurrence rate of binarity is significantly higher for TNOs still in the plane (unperturbed orbits). In less than 15 years, the Kuiper Belt has advanced from a hypothesis to a rich field of observational and theoretical research. It is telling us about the earliest days of the Solar System, and about events we can only hope to observe directly in analogous structures around young nearby stars. Hubble is at the forefront of both avenues of research. W The Pluto System

The Pluto system is revealed to be an unexpectedly complex multiple system in this image from Hubble’s Advanced Camera for Surveys. Pluto and Charon, the two brightest objects in the image orbit around a common center of mass that lies between them, a distinction that sets them apart from any previously known Solar System pair, but which they share in common with the bulk of trans-neptunian binaries. The two smaller satellites, Nix (closer to Pluto/Charon) and Hydra, were unseen in the glare of Pluto and Illustration by Ann Feild (STScI)

Charon until imaged by Hubble. Above: This illustration shows two different kinds of orbits on vastly different scales. The orbit around the Sun of They are in co-planar and nearly the trans-neptunian binary 1998 WW31 is shown as the light-red ellipse, which extends beyond Neptune and Pluto circular orbits around the com- into the swarm of more distant icy bodies known as the Kuiper Belt. The inset illustrates the mutual orbit of the two mon center of mass. components of the 1998 WW31 binary (for convenience, the position of the larger, brighter member of the pair is shown as fixed). From the orbit, the mass of the binary pair can be derived using classical physics.

Left: This image of 1999 OJ4, taken with Hubble’s Advanced Camera for Surveys, shows that this object is, in fact, a previously unresolved pair of nearly equal-sized objects in orbit around each other. Their small separation and faintness require Hubble’s unique combination of capabilities to see them.

24 Naming the Worlds Beyond Neptune

here are few issues that can spark a more spirited debate than what to name newly discovered objects Tin the Solar System. The naming process starts with a temporary designation by the Minor Planet Center (MPC). The MPC organizes and disseminates preliminary observational data needed to pin down the orbit, which is essential for the long-term study of newly found objects. The temporary designation comprises the year of discovery (four digits), the half-month interval within that year (one letter, skipping “I”), and a unique alphanumeric code for each object found in the two-week period. This code starts with A, runs through Z (again skipping “I”), and then repeats with an appended, subscripted number that increments each time the letter is used. For example, the temporary designation 2005 FY9 refers to the 249th—9 × 25 + 24—new object reported to the MPC in the period March 16–31, 2005. Typically, observations over a couple of years improve knowledge of an orbit to the point that the future position of the object can be predicted within some acceptable limits of uncertainty. At that point, the object is ready for a permanent serial number, which by convention, is written in parentheses. The number of small Solar System bodies with such good orbits is now in the hundreds of thousands. (For example, the object 2005 FY9 is now numbered 136472.) The permanent number is a signal to astronomers that an object is now a well-established member of the Solar System. It is interesting to note that approximately half of the trans-neptunian objects (TNOs) given temporary desig- nations are now “lost,” meaning that the initial estimates of their orbits were not sufficiently accurate to permit relocating them in follow-up observations, if, indeed, any such observations were ever attempted. These objects will not receive a permanent designation unless and until they are rediscovered at a future date. Once an object is permanently numbered, it is eligible for naming. The International Astronomical Union is responsible for the naming of astronomical objects, a mandate carried out for TNOs by its Committee on Small Body Nomenclature. This group has established several naming conventions for TNOs. All Quaoar must be named for mythological Hubble performed the first direct characters. Objects in resonances measurement of a KBO’s size by with Neptune (the ratio of orbital imaging the distant object known periods is equal to a ratio of as Quaoar (presented here in an two integers), like Pluto, are to artist’s concept). This icy world is be named for characters from approximately half the size of Pluto, underworld myths. Objects in making it one of the larger Kuiper low-inclination, low-eccentricity Belt Objects recently discovered. orbits are named for characters from creation myths. Objects orbiting between Jupiter and Neptune are named for the hybrid Centaurs. A recent extension of this convention calls for using the names of other mythological hybrid creatures for objects that cross the orbits of both Neptune and Saturn. With many of the more familiar names from Greek and Roman mythologies already in use, a rush has begun on names from the rich mythology of the wider world; (90377) Sedna, named for the Inuit goddess of the sea, is an example of this trend.

Illustration by Greg Bacon (STScI)

25 Galaxies over the Latter Sandra Faber is University Half of Cosmic Time Professor at the University of Marc Davis, [email protected], and California, and Astronomer/ Sandra M. Faber, [email protected] Professor at the University

of California Observatories, Galaxies are the basic systems of the universe. Like diamonds strewn across the sky, UC Santa Cruz. She has used their tiny points of light mark the cosmic landscape. They reveal its organization into superclusters of thousands of galaxies, which border the vast voids of empty space. the Hubble Space Telescope Galaxies make the universe interesting. Without them, the expansion of the universe to discover black holes at the would have diluted the cosmic soup into a thin broth of sterile and boringly diffuse Ggas. Instead, the excess gravity of tiny seeds of matter from the Big Bang slowed down cosmic centers of galaxies and to study expansion in regions that would become galaxies. The seeds drew in nearby gas, which eventually spawned the first generation of stars. Over billions of years, supernova explosions enriched the mix distant galaxy evolution. She is with oxygen, carbon, iron, and other elements that form only inside stars. These heavy elements Co-Principal Investigator of the are necessary to make planets such as Earth. The local gas consumed by star formation was replenished by fresh gas falling in from outside. By these cycles of stellar birth and death, galaxies DEEP 2 redshift survey and PI became fertile, self-sustaining ecosystems and evolved to become more and more suited for of the DEIMOS spectrograph, planets, and for life. “Red-and-dead” galaxies which was used for the survey. While we think this picture describes the evolution of most galaxies, for many it apparently does Marc Davis is Professor of not. In some galaxies, something intervenes to quench star formation by shutting off the supply Astronomy and Physics at UC Berkeley. He is a pioneer in redshift surveys and the analysis of galaxy clustering. He is the Principal Investigator of the DEEP 2 redshift survey, which is designed to study the evolution of galaxy properties and galaxy clustering as the universe evolved. Davis is a member of the National Academy of Sciences and the American Academy of Arts and Sciences.

Right: This new NASA Hubble Space Telescope image of the Antennae galaxies is the sharpest yet of this merging pair of galaxies. During the course of the collision, billions of stars will be formed. The brightest and most compact of these star-birth regions are called super star clusters, visible here as clumps of blue/white stars. As this essay explains, galaxy collisions producing massive bursts of stars might possibly lead over time to the formation of “red-and-dead” galaxies.

26 The AEGIS Field

The AEGIS picture contains one billion picture elements—the equivalent of 500 high-definition TV screens. It includes images of over 25,000 galaxies maturing to adulthood over the last several billion years.

of gas. This results in “red-and-dead” galaxies, which lack the characteristic blue tinge of freshly formed young stars. Such galaxies have given birth to all the stars and planetary systems they ever will, and for them the window of opportunity to create fresh habitats for life has closed. The number of red-and-dead galaxies has increased dramatically over the latter half of cosmic time. What mysterious process is killing off star formation in the universe? Currently, there are two different ideas to explain the origin of red-and-dead galaxies. The first is that some galaxies may fall into massive clusters, where intergalactic gas at millions of degrees is too hot to be collected. Starved of their gas supply, such galaxies would cease to form stars. An alternative idea is that occasional collisions of galaxies may trigger massive bursts of star formation, producing supernovae that sweep away the gas. Such collisions may also drive gas clouds toward the center of a galaxy, feeding a supermassive black hole and producing such intense emission from the active galactic nucleus that radiation pressure prevents other gas from falling into the galaxy. Hubble is the perfect tool for testing such theories. Its images can tease out fine details in the structures of distant galaxies, showing which ones are forming stars normally, which are colliding, and which are red and dead. Active galactic nuclei (AGN)—the bright accretion disks feeding supermassive black holes—stand out as bright centers, which are visible to great distances and far back in time. In fact, each Hubble image is a “core drilling” through space-time, because successive strata disclose information from increasingly earlier epochs. Knowing the distance to a galaxy is the same as knowing its age when we see it, which allows us to reconstruct the galaxy populations of previous eras. The AEGIS survey A new survey project called All-Wavelength Extended Groth Strip International Survey (AEGIS) has created one of the largest Hubble pictures to date. The image is 1/6º wide by 1º long, stretching twice the width of the full Moon. It is a mosaic of 63 tiles, each exposed through green and red filters, to produce diagnostic color images of some 25,000 galaxies bright enough for detailed study. The AEGIS team is counting the red-and-dead (quenched) galaxies and searching for circumstances—like collisions, AGN, and other factors—that may affect star formation on a galactic scale. A special feature of AEGIS is a rich array of supporting data from other space- and ground- based observatories—nine besides Hubble. The Chandra x-ray satellite locates black holes buried in dust clouds and invisible to Hubble. Together, the Galaxy Evolution Explorer (ultraviolet) and Spitzer (infrared) satellites measure all new star formation, including any starbursts hidden by dust. The second phase of the Deep Extragalactic Evolutionary Probe (DEEP 2) redshift survey from the Keck Observatory provides optical spectra of thousands of galaxies, from which distances, galaxy masses, and chemical compositions can be determined. Each facility contributes key information to create a full portrait of every object. Continued page 28

27 The galaxy CXO– Galaxies J141741.9 is an example from page 27 of how multispectral data fit together. The color Hubble image shows a highly disturbed object with clumps of newly formed stars. The brightest clump coincides with a bright x-ray source discovered by Chandra. This source is a quasi-stellar object (QSO) fueled by the clouds of gas being swallowed by a massive black hole. Ground-based data at millimeter wave- lengths show an exceptionally bright starburst, emitting more energy at visible wavelengths than the entire galaxy does, but the starburst is completely hidden by dense, overlying dust clouds. The direct radiation of the starburst can be measured only at far-infrared and radio wavelengths. At mid-infrared wavelengths, the Multiband Imaging Photometer on Spitzer can see hot dust, both close to the QSO and sur- The AEGIS field, rounding the young stars. At shorter infrared in the constel- wavelengths, Spitzer’s Infrared Array Camera lation Boötes, is can also see the QSO. one of the most CXO–J141741.9 is probably a pair of colliding intensively studied galaxies in which perturbed gas clouds have regions of the sky, burst into star formation and ignited a central with deep cover- black hole, producing the QSO. The intense age at all wave- releases of energy from both processes will lengths from radio probably sweep CXO–J141741.9 clean of gas waves to x-rays. after a few million years, which would mean Such panchromatic coverage provides that this galaxy is well on its way to becoming individual portraits quenched, red, and dead. of over 25,000 gal- A new tool for classifying galaxies axies, showing star formation and re- To find more objects like CXO–J141741.9, vealing factors that the AEGIS team has created a new tool to clas- may affect it. sify galaxy images in an objective, automated manner. The tool processes the brightness information in all the pixels of a galaxy’s image and decides what kind of galaxy it is. To classify galaxies as normal or disturbed, the tool mea- sures the degree of clumpiness in the image and computes the center-to-edge brightness contrast ratio. It arranges the normal galaxies along a star-forming sequence. It identifies fully quenched, red-and-dead galaxies, as well as systems that are colliding. Preliminary results with this tool suggest that the collision rate has held steady over the last 9 billion years. If galaxy collisions are very efficient in producing in red-and-dead galaxies, then the observed collision rate could fully account for the observed rate of growth of the Keck DEEP 2 spectroscopic redshift survey population of quenched galaxies. However, if Palomar near-IR WIRC JK survey only a fraction of galaxy collisions result in new Canada France DEEP 2 imaging survey red-and-dead galaxies, as we have reason to Chandra x-ray satellite believe, then starvation by hot intergalactic Spizter IRAC gas in galaxy clusters may also be important. VLA 6cm We expect that continuing analyses of AEGIS observations will help us resolve the true Graphic by Michael Marosy (GSFC) causes of quenching.

28 Hubble Spitzer/MIPS Spitzer/IRAC Chandra

Graphic by Michael Marosy (GSFC)

Above: The AEGIS field, in the constellation Boötes, is one of the most intensively studied regions of the sky, with deep coverage at all wavelengths from radio waves to x-rays. Such panchromatic coverage provides individual portraits of over 25,000 galaxies, showing star formation and revealing factors that may affect it.

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Dinosaurs Earth develops oxygen atmosphereLife forms on EarthSolar System birth Birth of oldest stars in solar neighborhoodQSO Era Birth of first galaxies

Graphic by Michael Marosy (GSFC)

Above: Hubble looks out in space and back in time to observe star-formation rates in over 25,000 galaxies as they looked as long ago as half the age of the universe. Blue indicates regions where star formation is ongoing, red where it has been quenched. Typical galaxies are displayed in three time zones from the distant past to more recent times. The numbers along the central spine of the figure are “look-back” times in billions of years, i.e., the time light has traveled to reach us. In each zone—8–9, 6–7, and 3–5 billion years—a gap separates blue galaxies to the left and red-and-dead to the right. The number of red-and- dead galaxies increases with the passage of time, symbolized here by the increasing number of examples of red-and-dead galaxies—two, four, and six—in the three time zones. (The six red-and-dead galaxies at lowest redshift appear to be somewhat bluer than those at higher redshift. This is an artifact of data processing. They are still obviously redder than the six star-forming galaxies to the left.) The shapes of the blue star-forming galaxies become more regular as material settles into orderly, rotating disks.

Continued page 30 29 Disturbed Light Distribution

colliding blends spheroids

disks Orderly Light Distribution

Spatially Extended Spatially Compact

0.8

spheroids blends 0.6 disks colliding The wide variety of galactic shapes and sizes is one of the most striking features of the deep, high-resolution AEGIS im- age. The automatic classification tool 0.4 assigns to norma-looking galaxies the labels “spheroid,” “disk,” or “blend,” cor- responding to normal nearby galaxies. The tool also measures the orderliness of

Morphological Fraction the light distribution to identify colliding 0.2 galaxies. Out to 9 billion years ago, more than 90% of galaxies have normal types and only 7% appear to be colliding. How- ever, the number of spheroids more than doubles over the same time, probably 0.0 due to collisions that result in mergers. 2468 Lookback Time in Billion Years

Graphic by Michael Marosy (GSFC)

The Milky Way before the Sun and Earth formed Galaxies from page 29 The AEGIS team is studying other properties of galaxy formation, too. From the new star-formation data, we find that each size of galaxy makes stars at a characteristic rate over cosmic time. From internal motions determined from Keck spectra, we find that only in the past few billion years have most disk galaxies (like our own Milky Way) stopped colliding with other galaxies and settled down to form ordered rotating disks. We are using the same spectra to measure how fast these galaxies synthesized heavy elements and enriched their interstellar gas to the level needed to make planetary systems. While we cannot look directly into the past to see our own galaxy forming and evolving, AEGIS data allow us to do the next-best thing—watch look-alikes of the Milky Way evolving billions of years ago, quite probably leading to the formation of suns and solar systems like our own. W

30 Hubble Snaps Close-up Views of Diverse Galaxies Images from the ANGST program

ubble’s Advanced Camera for Surveys provided these close-up views of four galaxies from a large survey of nearby galaxies, the ANGST (ACS Nearby Galaxy Survey Treasury) program. The survey explored a region called the “Local Volume,” and the galaxy distances ranged from 6.5 million light-years to 13 million light-years from Earth. The galaxies have very different masses and sizes and showcase the diversity of galaxies found in the ANGST study. Although the galaxies are separated by many light-years, they are presented as if they are all at the same distance to show their relative sizes. The ACS images reveal rich detail in the stellar populations and in the interstellar dust scattered between the stars. Hubble’s sharp views reveal the colors and brightnesses of individual stars, which astronomers used to derive the history of star formation in each galaxy. For more information, please visit: http://hubblesite.org/newscenter/ archive/releases/2008/35/.

NASA, ESA, J. Dalcanton, and B. Williams (University of Washington). Montage by Zolt Levay (STScI).

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The Institute’s website is: http://www.stsci.edu. Assistance is available at [email protected] or 800-544-8125. International callers can use 1-410-338-1082. For current Hubble users, program information is available at: http://presto.stsci.edu/public/propinfo.html. ST-ECF The current members of the Space Telescope Users Committee (STUC) are: Newsletter Pat McCarthy (chair), Carnegie Observatories, [email protected] he Space Telescope–European Coordinating Facility Martin Barstow, U. of Leicester Phil Nicholson, Cornell U. publishes a newsletter which, although aimed principally Peter Garnavich, U. of Notre Dame Robert O’Connell, U. of Virginia at European Space Telescope users, contains articles of general interest to the HST community. If you wish to Jim Green, U. of Colorado Alvio Renzini, INAF be included in the mailing list, please contact the editor Jean-Paul Kneib, OAMP Abi Saha, NOAO Tand state your affiliation and specific involvement in the Space Telescope Project. David Koo, UCSC Tommaso Treu, UCSB Lori Lubin, UCD Marianne Vestergaard, Tufts U. Richard Hook (Editor) Mario Mateo, U. of Michigan Space Telescope–European Coordinating Facility Karl Schwarzschild Str. 2 The Space Telescope Science Institute Newsletter is edited by Robert Brown, D-85748 Garching bei München [email protected], who invites comments and suggestions. Germany Technical Lead: Christian Lallo, [email protected] E-Mail: [email protected] Contents Manager: Sharon Toolan, [email protected] Design: Ann Feild, [email protected] To record a change of address or to request receipt of the Newsletter, please send a message to [email protected]. 31 Contents: Calendar

Cycle 17: Proposal Review and Science Program . . . . 1 JWST Partners Meeting (Munich) ...... 14–16 October 2008 Hubble Update ...... 2 ESA Senior Review (location TBD) ...... 15–16 October 2008 WFPC2 Closeout ...... 14 JWST SWG (Palo Alto) ...... 22–23 October 2008 NICMOS Update: Legacy Recalibration/Reprocessing . . 16 International Virtual Observatory Alliance Coordination Meeting . . 27–31 October 2008 Webb Confirmed for Implementation ...... 17 STIC meeting (STScI) ...... 3–4 November 2008 Status of the Webb Science Operations Center . . . . 18 STUC meeting (STScI) ...... 13–14 November 2008 National Virtual Observatory ...... 18 AAS meeting (Long Beach) ...... 4–8 January 2009 Hubble Fellow Program News ...... 20 Binaries (and More) in the Kuiper Belt ...... 22 Galaxies over the Latter Half of Cosmic Time . . . . . 26 Contact STScI ...... 31 Calendar ...... 32

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