Core Concept: Unraveling the Enigma of Fast Radio Bursts
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Report for the Academic Year 1995
Institute /or ADVANCED STUDY REPORT FOR THE ACADEMIC YEAR 1994 - 95 PRINCETON NEW JERSEY Institute /or ADVANCED STUDY REPORT FOR THE ACADEMIC YEAR 1 994 - 95 OLDEN LANE PRINCETON • NEW JERSEY 08540-0631 609-734-8000 609-924-8399 (Fax) Extract from the letter addressed by the Founders to the Institute's Trustees, dated June 6, 1930. Newark, New jersey. It is fundamental in our purpose, and our express desire, that in the appointments to the staff and faculty, as well as in the admission of workers and students, no account shall be taken, directly or indirectly, of race, religion, or sex. We feel strongly that the spirit characteristic of America at its noblest, above all the pursuit of higher learning, cannot admit of any conditions as to personnel other than those designed to promote the objects for which this institution is established, and particularly with no regard whatever to accidents of race, creed, or sex. TABLE OF CONTENTS 4 BACKGROUND AND PURPOSE 5 • FOUNDERS, TRUSTEES AND OFFICERS OF THE BOARD AND OF THE CORPORATION 8 • ADMINISTRATION 11 REPORT OF THE CHAIRMAN 15 REPORT OF THE DIRECTOR 23 • ACKNOWLEDGMENTS 27 • REPORT OF THE SCHOOL OF HISTORICAL STUDIES ACADEMIC ACTIVITIES MEMBERS, VISITORS AND RESEARCH STAFF 36 • REPORT OF THE SCHOOL OF MATHEMATICS ACADEMIC ACTIVITIES MEMBERS AND VISITORS 42 • REPORT OF THE SCHOOL OF NATURAL SCIENCES ACADEMIC ACTIVITIES MEMBERS AND VISITORS 50 • REPORT OF THE SCHOOL OF SOCIAL SCIENCE ACADEMIC ACTIVITIES MEMBERS, VISITORS AND RESEARCH STAFF 55 • REPORT OF THE INSTITUTE LIBRARIES 57 • RECORD OF INSTITUTE EVENTS IN THE ACADEMIC YEAR 1994-95 85 • INDEPENDENT AUDITORS' REPORT INSTITUTE FOR ADVANCED STUDY: BACKGROUND AND PURPOSE The Institute for Advanced Study is an independent, nonprofit institution devoted to the encouragement of learning and scholarship. -
Atmospheric Interpretation of Anomalous Terrestrial
Atmospheric Interpretation of Anomalous Terrestrial Emission Serendipitously Discovered in Radioastronomy Data at 1 Gigahertz Sarah Burke-Spolaor1, Ron Ekers1, and Jean-Pierre Macquart 2 1 CSIRO Astronomy and Space Sciences, PO Box 76, Epping NSW 1710, Australia [email protected] 2 ICRAR/Curtin Institute of Radio Astronomy, GPO Box U1987, Perth WA 6845, Australia Abstract A publication in the Astrophysical Journal [1] reported the discovery of swept-frequency, terrestrial emission in a search for astrophysical pulses. The emission's origin has yet to be determined; its attributes are atypical of known sources of terrestrial signals. We review the observed properties of the emission and present a simple model for a physical mechanism that could occur in the atmosphere to produce it. If this mechanism is the cause of the emission, its origin may lie in secondary effects of lightning production in the upper atmosphere. 1 Introduction Searches for isolated astronomical radio pulses have grown in popularity following a number of recent discoveries [e.g. 2-3]. The surfeit of Earth-origin (man-made and natural) pulses requires these searches to use techniques that discriminate target signals from terrestrial pulses. A basic feature of astronomical pulses is their frequency-dependent delay, which follows δt / f −2. This is an additive dispersion effect resulting from propagation through interstellar plasma that is negligible in locally-generated emission (see Fig. 1). Recently, sixteen terrestrial pulses with frequency-swept characteristics that mimic an astronomical dis- persion delay were reported [1]. They were found in data taken at sparse intervals over the years 1998{2003, using the multibeam receiver on Parkes Radio Telescope in Australia and a specialized back-end hardware that allows 96 spectral bands to be sampled across a 288 MHz bandwidth centered at f = 1:375 GHz. -
Female Fellows of the Royal Society
Female Fellows of the Royal Society Professor Jan Anderson FRS [1996] Professor Ruth Lynden-Bell FRS [2006] Professor Judith Armitage FRS [2013] Dr Mary Lyon FRS [1973] Professor Frances Ashcroft FMedSci FRS [1999] Professor Georgina Mace CBE FRS [2002] Professor Gillian Bates FMedSci FRS [2007] Professor Trudy Mackay FRS [2006] Professor Jean Beggs CBE FRS [1998] Professor Enid MacRobbie FRS [1991] Dame Jocelyn Bell Burnell DBE FRS [2003] Dr Philippa Marrack FMedSci FRS [1997] Dame Valerie Beral DBE FMedSci FRS [2006] Professor Dusa McDuff FRS [1994] Dr Mariann Bienz FMedSci FRS [2003] Professor Angela McLean FRS [2009] Professor Elizabeth Blackburn AC FRS [1992] Professor Anne Mills FMedSci FRS [2013] Professor Andrea Brand FMedSci FRS [2010] Professor Brenda Milner CC FRS [1979] Professor Eleanor Burbidge FRS [1964] Dr Anne O'Garra FMedSci FRS [2008] Professor Eleanor Campbell FRS [2010] Dame Bridget Ogilvie AC DBE FMedSci FRS [2003] Professor Doreen Cantrell FMedSci FRS [2011] Baroness Onora O'Neill * CBE FBA FMedSci FRS [2007] Professor Lorna Casselton CBE FRS [1999] Dame Linda Partridge DBE FMedSci FRS [1996] Professor Deborah Charlesworth FRS [2005] Dr Barbara Pearse FRS [1988] Professor Jennifer Clack FRS [2009] Professor Fiona Powrie FRS [2011] Professor Nicola Clayton FRS [2010] Professor Susan Rees FRS [2002] Professor Suzanne Cory AC FRS [1992] Professor Daniela Rhodes FRS [2007] Dame Kay Davies DBE FMedSci FRS [2003] Professor Elizabeth Robertson FRS [2003] Professor Caroline Dean OBE FRS [2004] Dame Carol Robinson DBE FMedSci -
Radio and Millimeter Continuum Surveys and Their Astrophysical Implications
The Astronomy and Astrophysics Review (2011) DOI 10.1007/s00159-009-0026-0 REVIEWARTICLE Gianfranco De Zotti · Marcella Massardi · Mattia Negrello · Jasper Wall Radio and millimeter continuum surveys and their astrophysical implications Received: 13 May 2009 c Springer-Verlag 2009 Abstract We review the statistical properties of the main populations of radio sources, as emerging from radio and millimeter sky surveys. Recent determina- tions of local luminosity functions are presented and compared with earlier esti- mates still in widespread use. A number of unresolved issues are discussed. These include: the (possibly luminosity-dependent) decline of source space densities at high redshifts; the possible dichotomies between evolutionary properties of low- versus high-luminosity and of flat- versus steep-spectrum AGN-powered radio sources; and the nature of sources accounting for the upturn of source counts at sub-milli-Jansky (mJy) levels. It is shown that straightforward extrapolations of evolutionary models, accounting for both the far-IR counts and redshift distribu- tions of star-forming galaxies, match the radio source counts at flux-density levels of tens of µJy remarkably well. We consider the statistical properties of rare but physically very interesting classes of sources, such as GHz Peak Spectrum and ADAF/ADIOS sources, and radio afterglows of γ-ray bursts. We also discuss the exploitation of large-area radio surveys to investigate large-scale structure through studies of clustering and the Integrated Sachs–Wolfe effect. Finally, we briefly describe the potential of the new and forthcoming generations of radio telescopes. A compendium of source counts at different frequencies is given in Supplemen- tary Material. -
Fast Radio Bursts: from a Handful to Hundreds with Chime/Frb
FAST RADIO BURSTS: FROM A HANDFUL TO HUNDREDS WITH CHIME/FRB KIYOSHI MASUI, ALEX JOSEPHY, AND MOHIT BHARDWAJ FOR THE CHIME/FRB COLLABORATION AAS PRESS BRIEFING JUNE 9, 2021 Correspondance to: [email protected] (857) 207-6121 FAST RADIO BURSTS Bright, brief (millisecond) flashes of radio light coming from other galaxies Likely neutron star/magnetar origin but otherwise poorly understood, limited by small numbers Distortion of signals (dispersion) carries record of structure travelled through CHIME/FRB COLLABORATION ARTWORK: ESA CANADIAN HYDROGEN INTENSITY MAPPING EXPERIMENT FAST RADIO BURST INSTRUMENT (CHIME/FRB) CHIME/FRB COLLABORATION chime-experiment.ca CHIME/FRB CATALOG MAP OF EVERY KNOWN FRB UP TO JULY 2018 CHIME/FRB COLLABORATION CHIME/FRB CATALOG MAP OF EVERY KNOWN FRB UP TO JULY 2019 CHIME/FRB COLLABORATION CATALOG CONTENTS 535 FRBs observed between July 2018 and July 2019 Includes 61 bursts from 18 repeating sources Properties of each burst: time, sky location, brightness, duration, dispersion, etc. See CHIME/FRB Collaboration 2021 CHIME/FRB COLLABORATION A NEW PHASE OF FRB SCIENCE First large sample of FRBs Enables precision studies of the FRB Population Opportunity to study large- scale structure of the Universe CHIME/FRB COLLABORATION POPULATION MODELLING Simulating fake bursts allows us to understand our observational biases Measure brightness distribution and rate: ~800 bright FRBs per day CHIME/FRB COLLABORATION SKY DISTRIBUTION Must consider sensitivity, telescope response, and galactic foreground. After correcting for these effects, we find strong evidence for uniform distribution. See: Josephy et al. 2021 CHIME/FRB COLLABORATION LARGE SCALE STRUCTURE Find FRBs to be correlated with galaxies, for a wide redshift range Ushering in new era of FRB cosmology See: Rafiei-Ravandi et al. -
Recycling' a Star (W/Animations) 21 May 2009
The cosmos is green: Researchers catch nature in the act of 'recycling' a star (w/Animations) 21 May 2009 survey has found many new pulsars, but this one is truly special -- it is a very freshly 'recycled' pulsar that is emerging straight from the recycling plant." said Archibald. The McGill researchers worked with Asst. Prof. Ingrid Stairs of UBC and Scott Ransom of NRAO as well as others from the collaboration to carry out more observations of this unusual pulsar. Pulsars are rapidly rotating, highly magnetized neutron stars, the remnants left after massive stars have exploded as supernovae. Pulsars emit lighthouse-like beams of radio waves that sweep around as the star rotates. Most rotate relatively Neutron star with accretion disk (left) drawing material slowly, ten times a second or less, and their from companion star (right). CREDIT: Bill Saxton, magnetic fields ordinarily slow them down even NRAO/AUI/NSF further over the course of millennia. Millisecond pulsars, however, rotate hundreds of times a second. (PhysOrg.com) -- For the first time, researchers "We know normal pulsars typically pulsate in the have observed a singular cosmic act of rebirth: the radio spectrum for one million to ten million years, transformation of an ordinary, slow-rotating pulsar but eventually they slow down enough to die out," into a superfast millisecond pulsar with an almost explained Kaspi. "But a few of these old pulsars get infinitely extended lifespan. 'recycled' into millisecond pulsars. They end up spinning extremely fast, and then they can pulsate The discovery was made during a large radio sky forever. -
The Development of a Small Scale Radio Astronomy Image Synthesis Array for Research in Radio Frequency Interference Mitigation
Brigham Young University BYU ScholarsArchive Theses and Dissertations 2005-09-05 The Development of a Small Scale Radio Astronomy Image Synthesis Array for Research in Radio Frequency Interference Mitigation Jacob L. Campbell Brigham Young University - Provo Follow this and additional works at: https://scholarsarchive.byu.edu/etd Part of the Electrical and Computer Engineering Commons BYU ScholarsArchive Citation Campbell, Jacob L., "The Development of a Small Scale Radio Astronomy Image Synthesis Array for Research in Radio Frequency Interference Mitigation" (2005). Theses and Dissertations. 673. https://scholarsarchive.byu.edu/etd/673 This Thesis is brought to you for free and open access by BYU ScholarsArchive. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. THE DEVELOPMENT OF A SMALL SCALE RADIO ASTRONOMY IMAGE SYNTHESIS ARRAY FOR RESEARCH IN RADIO FREQUENCY INTERFERENCE MITIGATION by Jacob Lee Campbell A thesis submitted to the faculty of Brigham Young University in partial fulfillment of the requirements for the degree of Master of Science Department of Electrical and Computer Engineering Brigham Young University December 2005 Copyright c 2005 Jacob Lee Campbell All Rights Reserved BRIGHAM YOUNG UNIVERSITY GRADUATE COMMITTEE APPROVAL of a thesis submitted by Jacob Lee Campbell This thesis has been read by each member of the following graduate committee and by majority vote has -
Long-Term Evolution and Physical Properties of Rotating Radio Transients
LONG-TERM EVOLUTION AND PHYSICAL PROPERTIES OF ROTATING RADIO TRANSIENTS by Ali Arda Gençali Submitted to the Graduate School of Engineering and Natural Sciences in partial fulfillment of the requirements for the degree of Master of Science Sabancı University June 2018 c Ali Arda Gençali 2018 All Rights Reserved LONG-TERM EVOLUTION AND PHYSICAL PROPERTIES OF ROTATING RADIO TRANSIENTS Ali Arda Gençali Physics, Master of Science Thesis, 2018 Thesis Supervisor: Assoc. Prof. Ünal Ertan Abstract A series of detailed work on the long-term evolutions of young neutron star pop- ulations, namely anomalous X-ray pulsars (AXPs), soft gamma repeaters (SGRs), dim isolated neutron stars (XDINs), “high-magnetic-field” radio pulsars (HBRPs), and central compact objects (CCOs) showed that the X-ray luminosities, LX, and the rotational prop- erties of these systems can be reached by the neutron stars evolving with fallback discs and conventional dipole fields. Remarkably different individual source properties of these populations are reproduced in the same model as a result of the differences in their initial conditions, magnetic moment, initial rotational period, and the disc properties. In this the- sis, we have analysed the properties of the rotating radio transients (RRATs) in the same model. We investigated the long-term evolution of J1819–1458, which is the only RRAT detected in X-rays. The period, period derivative and X-ray luminosity of J1819–1458 11 can be reproduced simultaneously with a magnetic dipole field strength B0 ∼ 5 × 10 G on the pole of the neutron star, which is much smaller than the field strength inferred from the dipole-torque formula. -
Small-Scale Anisotropies of the Cosmic Microwave Background: Experimental and Theoretical Perspectives
Small-Scale Anisotropies of the Cosmic Microwave Background: Experimental and Theoretical Perspectives Eric R. Switzer A DISSERTATION PRESENTED TO THE FACULTY OF PRINCETON UNIVERSITY IN CANDIDACY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY RECOMMENDED FOR ACCEPTANCE BY THE DEPARTMENT OF PHYSICS [Adviser: Lyman Page] November 2008 c Copyright by Eric R. Switzer, 2008. All rights reserved. Abstract In this thesis, we consider both theoretical and experimental aspects of the cosmic microwave background (CMB) anisotropy for ℓ > 500. Part one addresses the process by which the universe first became neutral, its recombination history. The work described here moves closer to achiev- ing the precision needed for upcoming small-scale anisotropy experiments. Part two describes experimental work with the Atacama Cosmology Telescope (ACT), designed to measure these anisotropies, and focuses on its electronics and software, on the site stability, and on calibration and diagnostics. Cosmological recombination occurs when the universe has cooled sufficiently for neutral atomic species to form. The atomic processes in this era determine the evolution of the free electron abundance, which in turn determines the optical depth to Thomson scattering. The Thomson optical depth drops rapidly (cosmologically) as the electrons are captured. The radiation is then decoupled from the matter, and so travels almost unimpeded to us today as the CMB. Studies of the CMB provide a pristine view of this early stage of the universe (at around 300,000 years old), and the statistics of the CMB anisotropy inform a model of the universe which is precise and consistent with cosmological studies of the more recent universe from optical astronomy. -
ÉMILIE PARENT Email: [email protected] Ph.D
ÉMILIE PARENT Email: [email protected] Ph.D. Candidate, Department of Physics, McGill University, 3600 rue University, Montreal QC, H3A 2T8, Canada EDUCATION . Candidate for Ph.D., Physics, McGill University 2017 - present Supervisor: Prof. Victoria Kaspi Graduation expected by summer 2021 M.Sc., Physics, McGill University 2015 - 2017 Thesis: A Search for Long-Period Pulsars with a Fast-Folding Algorithm in the PALFA Survey Supervisor: Prof. Victoria Kaspi B.Sc. (Hons.) Physics, Bishop's University 2012 - 2015 Thesis: Light-Curves Calibration of Type Ia Supernovae Supervisor: Prof. Lorne Nelson Diplôme d'étude collégial en Sciences de la nature, Cégep de Sherbrooke 2009 - 2011 RESEARCH . Interests: Pulsars and Fast Radio Bursts searching, software development & searching pipelines, pulsar timing and population studies, formation and evolution of millisecond pulsars and binary systems PALFA Survey 2015 - present ● Lead and coordinate timing efforts (proposal writing, observation planning, data management, analyses, publication, etc.) ● Lead of searching pipeline operation and development ● Survey and timing-data quality monitoring, and related communications with Arecibo ● Act as liaison with the CHIME/Pulsar and CHIME/FRB teams for collaborative data sharing purposes ● Sensitivity analysis of the survey to long-period pulsars ● Timing analysis of regular pulsars and millisecond pulsars, and searching for high-energy pulsations Green Bank Northern Celestial Cap Pulsar Survey 2017 - present ● Maintenance of the survey public -
What Can Fast Radio Bursts Teach Us About Magnetars?
What Can Fast Radio Bursts Teach Us About Magnetars? Fast radio bursts (FRBs) are mysterious pulses of radio emission that last only milliseconds, but put out as much energy as our sun produces over several days. Astrophysicists have many reasons to think they originate from magnetars, highly magnetized neutron stars. A magnetar may have a magnetic field of 10^14 Gauss, thousands of times stronger than a typical neutron star (just for comparison, the magnetic field of the sun is about 5 Gauss). What can we learn about magnetars from FRBs, considering the firehose of data expected in the next decade? As brief as FRB’s are, there are features in the radio emission that can be quasi-periodic and may be caused by oscillations of the crust and even core of the magnetar. We find some of these reported "trains" of FRBs are consistent with twisting “torsional” oscillations of magnetars seen in our galaxy. It is possible that FRBs offer opportunities to study the crust and internal structure of magnetars and could help constrain the distance of some of these objects. If our interpretation is correct, it represents a revolution in our ability to study magnetars. By combining observations from radio, gamma-rays and x-rays, we may be able to test our models of the interiors of some of the most dramatic objects in the universe, providing a laboratory of fundamental physics in extreme conditions. We expect a large amount of data from these objects in the next few years, but we’ll particularly require more detailed radio observations to further understand them. -
The Very Small Array
The Very Small Array Project: VSA PI: Dr. H. Paul Shuch, Exec. Dir., The SETI League, Inc. ([email protected]) Description and Objectives: A test platform for future research-grade radio telescopes, the Very Small Array is a low-cost effort to combine the collecting area of multiple off-the-shelf backyard satellite TV dishes into a highly capable L-band observing instrument. A volunteer effort of the grassroots nonprofit SETI League, the VSA is being built in the Principal Investigator’s backyard, with member donations and modest grant funding. A US patent has been issued for our technique of employing combined analog and digital circuitry for simultaneous total power radiometry, spectroscopy, and aperture synthesis interferometry. Key Features of Instrument: Schedule Milestones: Phase 0: Paper design, single-dish test bed; § 8 ea. 1.8 meter reflectors in Mills Cross array US patent #6,593,876 (issued 2003) § Offset feeds for non-blocked aperture Phase 1: Physical Structures – (completed 2004) (masts, az/el mounts, dishes, feeds, § Meridian transit mode w/ elevation rotation conduit, junction boxes cables) § Dual Orthogonal Circular Polarizations Phase 2: Front-end electronics (in process 2005) Phase 3: Back-end electronics + DSP (planned for 2007) § Full ‘water-hole’ coverage, 1.2 – 1.7 GHz Applications: § Simultaneous total power radiometry, spec- § Meridian transit all-sky SETI survey troscopy, and interferometry in real time § Parasitic Astrophysical Survey § Targeted SETI in direction of known exoplanets Partners: § Quick-response verification of candidate SETI signals American Astronomical Society, ARRL TRL = 3 Foundation, Microcomm Consulting Revised: 12 May 2005 Keywords: Radio Telescope, Phased Array, Mills Cross, Radiometry, Spectroscopy, Interferometry, SETI.