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- Biological Physics
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Observational Astrophysics & Cosmology
Ph.D., California/Berkeley, 1988.
S. Chandrasekhar Distinguished Service Professor, Dept. of Astronomy & Astrophysics, Dept. of Physics, Kavli Institute for Cosmological Physics, Enrico Fermi Institute, and the College.
Deputy Director, Kavli Institute for Cosmological Physics.
Experimental physics, astrophysics and cosmology, observations and new instrumentation.
Observational cosmology using new instruments to measure the temperature and polarization anisotropy of the Cosmic Microwave Background (CMB) radiation and the Sunyaev-Zeldovich (SZ) effects. Leader of the 10 meter South Pole Telescope (SPT) project, which recently completed a survey (SPT-SZ survey) of 2500 square degrees in three bands with unprecedented sensitivity and resolution. The SPT is now conducting sensitive polarization-sensitive CMB survey (SPT-POL) over 500 square degrees. In addition to increased precision of the cosmological parameters and tests of Inflation, the SPT data has allowed investigations of extensions to the standard model, such as the number and masses of the neutrinos, and the nature of dark energy. Furthermore, the high resolution of the SPT measurements also allows us to detect directly the emergence and evolution of structure in the universe through the subtle, small-angular scale distortions they impart on the background, such as gravitational lensing from the mass in the universe and the scattering from ionized gas (the SZ effects).
Through a new joint Chicago/Argonne superconducting detector development collaboration, the SPT group is building a new receiver, SPT-3G, with over 15,000 detectors to increase the polarization mapping speed by an order of magnitude. The SPT-3G survey will cover 2500 square degrees with unprecedented sensitivity to place constraints on the energy scale of inflation, on dark energy, on the reionization of the universe, and on the first bursts of star forming galaxies in the universe. Carlstrom is also leader of the CARMA SZ imaging program which is being upgraded with new receivers built at Chicago to provide unprecedented imaging of the SZ effect of distant galaxies clusters. By exploiting the redshift independence of the SZ brightness the CARMA SZ will be used to quickly follow-up and verify all high redshift clusters candidates found in the eRosita X-ray satellite survey and used to constrain cosmology through measurement of the growth of structure in the universe.
Past Phd Students: Rachel Akeson (1996); Laura Grego(1999); Gil Holder (2001); Erik D. Reese (2001); Nils Halverson(2002); John Kovac (2003); Samuel LaRoque (2005); Daisuke Nagai (2005); Joaquin Vieira (2009); Ryan Keisler (2010); Matthew Sharp (2008); Christopher Greer (2012).
Current PhD students: Zubair Abdulla (A&A); Lindsey Bleem (Physics, PhD expected Spring 2013); Abigail Crites (A&A PhD expected Summer 2013); Laura Mocanu (A&A); Tyler Natoli (Physics); Kyle Story (Physics).
Ph.D., University of South Carolina, 1992.
Professor, Dept. of Physics, Enrico Fermi Inst., and the College.
Experimental physics, neutrino and astroparticle physics.
Juan Collar's homepage
My main interest is in the development of new methods for the detection for hypothetical astroparticles (WIMPs, axions, magnetic monopoles, any yet-to-be-discovered component of cosmic rays that might constitute a fraction of the 'dark matter'). Evidently, this is all risky business but I am interested in both journey and destination: the extreme levels of sensitivity sought in some of these experiments force us in the field to devise new detection approaches and to try to stay aware of the latest advances in particle detector technology. It is all a very enjoyable challenge. I am also attracted to other exotica such as double-beta decay (as part of the MAJORANA collaboration) and some 'hard' problems in neutrino detection (coherent neutrino scattering, detection of the relic neutrino sea). I enjoy the condensed-matter aspects of detector development, in particular the area of interactions between radiation and matter. I get easily excited about cross-disciplinary endeavors and real-life applications of detectors that may otherwise be chasing ghost particles.
Together with collaborators at the Groupe de Physique des Solides (Universite Paris VII), University of Lisbon, and Pacific Northwest National Laboratory, I developed large-mass, low-background superheated droplet detectors (SDDs) dedicated to WIMP (Weakly Interacting Massive Particle) searches (The SIMPLE dark matter search). In Chicago I was able to start investigating the possibility of making large bubble chambers stable enough for the same purpose. Much progress has been made (the Chicagoland Observatory for Underground Particle Physics, COUPP, using CF3I as an optimal WIMP target). At CERN I am involved in CAST, a search for solar axions using a decommissioned LHC test magnet, an interesting astroparticle spin-off from the Large Hadron Collider effort. More recently we started work on the application of new detector technologies to neutrino detection via coherent nuclear scattering. A reactor experiment, sensitive for the first time to this interesting neutrino process, is expected to start in 2006.
- Superheated Microdrops as Cold Dark Matter Detectors. J.I. Collar. Phys. Rev. D 54, R1247, 1996.
- Experimental Search for Solar Axions Via Coherent Primakoff Conversion in a Germanium Spectrometer. F.T. Avignone III et al. Phys. Rev. Lett. 81, 5068, 1998.
- A Decommissioned LHC Model Magnet as an Axion Telescope. C.E. Aalseth et al. Nucl. Instr. Meth. A 425, 482, 1999.
- Neutrinoless double-beta decay of Ge-76.: First results from the International Germanium Experiment (IGEX) with six isotopically enriched detectors. C.E. Aalseth et al. Phys. Rev. C 59, 2108, 1999.
- Exotic Heavily Ionizing Particles can be Constrained by the Geological Abundance of Fullerenes. J.I. Collar and K. Zioutas. Phys. Rev. Lett. 83, 3097, 1999.
- First Dark Matter Limits from a Large-Mass, Low-Background Superheated Droplet Detector. J.I. Collar et al. Phys. Rev. Lett. 85, 3083, 2000.
- More recent publications
Ph.D., Chicago, 1955.
University Professor Emeritus, Dept. of Physics, Dept. of Astronomy and Astrophysics, and Enrico Fermi Institute.
Experimental physics, particle physics, ultra-high energy gamma-ray astronomy.
James Cronin and University of Leeds professor Alan Watson lead an international project to study the nature and origin of rare but extremely powerful, high-energy (>1019 eV), cosmic rays that periodically bombard Earth. The project includes more than 250 scientists from nineteen nations.
The scientists will practice a new form of astronomy rooted in particle physics. Construction of the Pierre Auger Observatory, a giant detector array near the cities of Malargue and San Rafael in Argentina's Mendoza Province, will be completed by 2003, but researchers plan to begin observations as early as 2001. The site will contain 1600 particle detection stations 1.5 kilometers apart, arranged in a giant grid covering 3000 square kilometers, an area about the size of the state of Rhode Island. The Auger Project collaborators hope later to construct a complementary northern hemisphere observatory which, together with the southern observatory, would allow studies of cosmic rays from the entire sky.
- Particle Astrophysics. B. Sadoulet and J. Cronin. Physics Today 53, 1991.
- Search for Discrete Sources of 100 TeV Gamma Radiation. J.W. Cronin et al. Phys. Rev. D45, 4385, 1992.
- A Northern Sky Survey for Astrophysical Point Sources of 100 TeV Gamma Radiation. T.A. McKay, et al. Astrophysical J. 417, 742, 1993.
- Observation of the Shadows of the Moon and Sun Using 100 TeV Cosmic Rays. A. Borione, et al. Physical Review D49, 1171, 1994.
- Cosmic Rays at the Energy Frontier. J. Cronin, T.K. Gaisser, S.P. Swordy. Scientific American 276, 1, 44, 1997.
- Cosmic Rays: The Most Energetic Particles in the Universe. J.W. Cronin. Rev. Mod. Phys. 71, S165, 1999.
Ph.D., Università degli Studi di Pavia, Italia, 2005.
Assistant Professor, Dept. of Physics, Enrico Fermi Institute, Kavli Institute for Cosmological Physics, and the College.
Experimental physics, dark matter and astroparticle physics
I have always been fascinated by fundamental physics, the kind of physics that is able to change our way of looking at the surrounding world and can provide a deeper understanding of how nature works. At the same time I have always been attracted by small scale experiments, those human-sized experiments where you can understand the entire experimental setup, in all its small details. Moreover I enjoy designing detectors, operating them and analyzing the collected data. These interests naturally brought me towards the field of rare events physics and, more specifically, toward Dark Matter direct searches. This area of research has a huge potential for discovery and the capability of providing experimental results that affect the foundation of our physics theories.
My activities, until now, have been focused on the development of liquid argon two-phase Time Projection Chamber (TPC) technology for Dark Matter direct detection. During my Ph.D. I was involved in the design, construction and operation of the WArP-2.3kg prototype, the first and still the only argon detector to have set a limit on the WIMP (Weakly Interacting Massive Particles) interaction rate.
More recently, starting from 2008, I am working on the DARKSIDE project (see darkside.lngs.infn.it), of which I am a co-founder, together with colleagues at Princeton University, Temple University, University of California Los Angeles, University of Amherst and FermiLab. DARKSIDE combines two-phase argon and organic liquid scintillator technologies: the use of depleted argon as a target in a two-phase argon TPC, coupled with a powerful neutron veto based on Borexino technology results in a unique detector for Dark Matter search, sensitive to extremely rare and low-energy nuclear recoils, possibly induced by WIMPs and capable of achieving background-free conditions. DARKSIDE-50, the first physics detector of the DarkSide family, will be deployed at Gran Sasso Underground Laboratory in Italy during the first quarter of 2013. DarkSide-50 has now become an international collaboration, including other institutions from US and Europe.
“Light Yield in DarkSide-10: a Prototype Two-phase Liquid Argon TPC for Dark Matter Searches”, Astroparticle Physics, Volume 49, September 2013, Pages 44-51.
- "Observation of the dependence on drift field of scintillation from nuclear recoils in liquid argon" Phys. Rev. D 88, 092006 (2013).
“Precision measurement of the 7Be solar neutrino interaction rate in Borexino”, Physical Review Letters 107, 141302 (2011).
“Effects of Nitrogen and Oxygen contaminations in liquid Argon”, Nuclear Instruments and Methods A 607, 169 (2009).
“First results from a Dark Matter search with liquid Argon at 87 K in the Gran Sasso Underground Laboratory”, Astroparticle Physics 28, 495 (2008)
“Discovery of underground argon with low level of radioactive 39Ar and possible applications to WIMP dark matter detectors”, Nuclear Instruments and Methods A 587, 46 (2008).
“Measurement of the specific activity of 39Ar in natural argon”, Nuclear Instruments and Methods in Physics A 574, 83 (2007).
Ph.D., California, Berkeley, 1951.
Samuel K. Allison Distinguished Service Professor Emeritus, Dept. of Physics, Dept. of Astronomy & Astrophysics, Enrico Fermi Institute.
Experimental physics, infrared astronomy.
Hildebrand and his students, former students, and other colleagues, study the properties of interstellar magnetic fields and interstellar dust by means of far-infrared photometry and polarimetry. They map the field configurations of collapsing clouds, filamentary clouds, and rotating clouds. They use the angular dispersion of field vectors to determine field strengths, turbulent fractions, and size-distributions of turbulent eddies. By 2012, their observations at the Caltech Submillimeter Observatory, will be supplemented by far infra-red polarimetry with SOFIA, the Stratospheric Observatory for Infrared Astrometry.
- The Determination of Cloud Masses and Dust Characteristics from Submillimeter Thermal Emission. R. H. Hildebrand. 1983, Q. J. R. Astron. Soc. 24, pp 267 - 282.
- Magnetic Fields and Stardust. R. H. Hildebrand. 1988, Q. Jl. R. astr. Soc., 29, 327 - 351.
- The Magnetic Field in the Dust Ring at the Center of the Galaxy. R. H. Hildebrand, D. P. Gonatas, S. R. Platt, X. D. Wu, J. A. Davidson, M. W. Werner, G. Novak, M.Morris. 1990, Astrophys. J., 362, 114 - 119.
- The Far-Infrared Polarization Spectrum: First Results and Analysis. R. H. Hildebrand, J. L. Dotson, C.D.Dowell, D. A. Schleuning, and J. E. Vaillancourt. 1999, ApJ, 516: 834 - 842.
- A Primer on Far-Infrared Polarimetry. R. H. Hildebrand, J. A. Davidson, J. L.Dotson, C. D. Dowell, G. Novak, and J. E. Vaillancourt. 2000, PASP, 112, 1215 - 1235. See Errata 2000, PASP, 112, 1620.
- On the Correlation between Magnetic Fields in Molecular Cloud Cores and Fields in the Inter-Cloud Medium. Hua-bai Li, C. Darren Dowell, Alyssa Goodman, Roger Hildebrand & Giles Novak. 2009, ApJ, 704, 891.
- Dispersion of Magnetic Fields in Molecular Clouds. II. Martin Houde, John E. Vaillancourt, Roger H. Hildebrand, Shadi Chitsazzadeh, & Larry Kirby 2009, ApJ, 706, 1504-1516.
- 350 μm Polarimetry from the Caltech Submillimeter Observatory. J. L., Dotson, J. A. Davidson, C. D. Dowell, L. Kirby, R. H. Hildebrand, and J. E., Vaillancourt 2010 , ApJS. 186 (2010) 406-426.
Ph.D., Princeton, 1979.
Professor, Dept. of Astronomy & Astrophysics, Dept. of Physics, Enrico Fermi Institute, and the College.
Experimental astrophysics, infrared astrophysics, observational cosmology.
The TopHat experiment is a balloon-borne Cosmic Microwave Background (CMBR) anisotropy measurement designed to measure 5% of the sky in a region around the south celestial pole. The bolometric instrument has five channels sensitive to frequencies from 150 to 600 GHz. It is designed to have good rejection of galactic dust foreground emission and have sensitivity of about 25 muK RMS per 20 arcminute beam. To minimize systematic errors, the 1-M telescope is flown on top of a high altitude balloon in a circumpolar flight. This position permits observations at high elevation angle and with an extensive ground-screen with no strong sources high in the sky. The instrument is to fly in late December 1999 or January 2000 with a flight lasting about 10 days. With its sky coverage and sensitivity, the instrument will determine the shape of the CMBR anisotropy power spectrum in the region enveloping the predicted position of the first "Doppler Peak." The l-space resolution is high enough to easily resolve and measure the position and heights of the first two peaks in the power spectrum.
The Microwave Anisotropy Probe (MAP) satellite, scheduled to fly in December 2000, will measure the Cosmic Microwave Background Radiation (CMBR) aniostropy over the full sky in five frequency bands from 22 to 100 GHz. The angular resolution of the highest frequency is 12 arcminutes making the instrument sensitive to the CMBR angular power spectrum from l=2 to 500. Launched into an orbit that takes the satellite to the earth-sun L2 point, MAP will have extremely low systematic errors and with the complete sky coverage and sensitivity will answer many of the key cosmological questions of interest.
The Center for Astrophysical Research in Antarctica (CARA) is an NSF Science and Technology Center (STC) which began in February 1991. The center supports several astrophysical experiments, all based at the (South Pole Station, which have as a common thread the investigation of the evolution of astrophysical structure. The investigations range over scales from the measurement of the Cosmic Microwave Background Radiation (CMBR) anisotropy to measurements leading to a better understanding of star forming regions. The experiments are also related in that they all are made at centimeter to micron wavelengths which requires that they be carried out at a very cold dry site such as the South Pole. This is because the emission from water vapor in the atmosphere and the telescopes themselves limit the sensitivity for ground-based measurements in this spectral range. The experiments being carried out by CARA include: AST/RO, the Antarctic Submillimeter Telescope and Remote Observatory; Viper, a 2-M telescope optimized to observe the anisotropy of the CMBR and other low-surface brightness objects; Abu, a 1024 x 1024 element detector array; and the Degree Angular Scale Interferometer (DASI), an interferometric CMBR anisotropy experiment.
Visit the Department of Astronomy and Astrophysics.
- Statistical Comparison of the MSAM-92 and MSAM-94 Results. C. A. Inman et al. Submitted January 1996 to Ap.J.
- A Balloon-Borne Millimeter-Wave Telescope for Cosmic Microwave Background Anisotropy Measurements. D.J. Fixsen et al. In press, Ap.J.
- MSAM 1-94: Repeated Measurement of Medium-Scale Anisotropy in the Cosmic Microwave Background Radiation. E.S. Cheng et al. Ap.J. 456, L71, 1996.
- Frequency Selective Bolometers. M. S. Kowitt et al. In press Applied Optics.
- Cosmic Temperature Fluctuations from Two Years of COBE DMR Observations. C.L. Bennett et al. Ap.J. 436, 423, 1994.
Updated 3/1999 or later
Ph.D., Bonn, 1964.
Prof Emeritus, Dept of Physics, Enrico Fermi Inst, and the College.
Experimental physics, cosmic rays, high-energy astrophysics.
Our research in high energy astrophysics includes the following topics:
Origin of high energy cosmic rays. Particle acceleration is a ubiquitous process in nature that occurs in all astronomical settings, from the surface of the sun to exotic, distant galaxies. In our galaxy, shock fronts from supernova explosions appear to be the sites where cosmic rays are accelerated over a large range of energies. However, the details of these processes are still poorly understood, and at the highest energies, above 1015 eV, other and as yet unknown sources of cosmic rays must exist. We aim to obtain observational constraints on the various models proposed for the origin of cosmic ray particles through precise measurements of the elemental composition and energy spectra of the individual cosmic ray components. Based on a series of investigations on high-altitude balloons and on the Space Shuttle, we have constructed a new and very large instrument, TRACER, that uses transition radiation detectors to permit measurements in the presently unexplored energy region between 1014 and 1015 eV. This detector exhibits a large sensitive area of nearly 5m2, weighs about 3 tons, and is carried by stratospheric balloons above the earth's atmosphere at a height of nearly 40 km above ground. A first balloon flight was conducted in 1999, and a long-duration flight to circle the Northern Hemisphere for about two weeks will be launched in 2002. TRACER also serves as a prototype for an instrument that may become part of the ACCESS mission which is now under consideration by NASA. ACCESS will be the largest cosmic ray detector ever flown in space, and will be mounted on the International Space Station for a duration of 3-4 years.
Search for anti-particles in the cosmic rays. Positrons and anti-protons are the only antiparticle species detected thus far in the cosmic radiation. They are generated subsequent to nuclear interactions in interstellar space and therefore provide an interesting probe on the structure of the interstellar medium and on the propagation of particles through the galaxy. However, there might also be more exotic contributions to the observed intensities of these particles, for instance, from the decay of hypothetical dark matter particles. These issues are studied with a balloon borne detector system, the High-Energy Antimatter Telescope (HEAT), which includes a superconducting magnet spectrometer. This instrument has been successfully flown in 1994 and 1995 to measure the flux of positrons and electrons over a wide energy range. At present, a modified detector system is used for the observation of high-energy antiprotons in balloon flights in 2000 and 2001. This work is conducted jointly with Simon Swordy and collaborators at several other institutions.
Gamma-ray astronomy. A major frontier area in gamma ray astronomy is the region of high energies, from about 100 GeV to several thousand GeV. In this energy region, supernova remnants in our galaxy could be identified, demonstrating that these are indeed the sites where cosmic rays are generated, and exciting discoveries wait to be made with the observation of extragalactic objects. Detectors in space do not have sufficient sensitivity for these observations, but arrays of Cherenkov telescopes on the ground can observe the gamma-ray showers generated in the Earth's atmosphere. We participate in the construction of the VERITAS installation in Arizona which has just begun and should lead to a 7-telescope array in 3-4 years. This work is conducted jointly with Simon Swordy, and in collaboration with a number of institutions in the US and in Europe.
- Performance of the HEAT Spectrometer for Cosmic Ray Electrons and Positrons. D. Müller (for the HEAT collaboration). Nucl. Instr. and Methods A367, 71, 1995.
- Towards the Knee: Direct Measurements of the Cosmic-Ray Composition with Electronic Detectors. D. Müller, E. Diehl, F. Gahbauer, P. Meyer, S. Swordy. Adv. in Space Res. 19, 719, 1997.
- Energy Spectra and Relative Abundances of Electrons and Positrons in the Galactic Cosmic Radiation. S.W. Barwick, J.J. Beatty, C.R. Bower, C. Chaput, S. Coutu, G. deNolfo, D. Ficenec, J. Knapp, D.M. Lowder, S. McKee, D. Müller, J.A. Musser, S.L. Nutter, E. Schneider, S.P. Swordy, G. Tarlé, A.D. Tomasch, E. Torbet. Ap. J. 498, 779, 1998.
- Cosmic-Ray Positrons: Are there Primary Sources? S. Coutu, S.W. Barwick, J.J. Beatty, A. Bhattacharyya, C. R. Bower, C. Chaput, G. deNolfo, M.A. DuVernois, A. Labrador, S. McKee, D. Müller, J.A. Musser, S.L. Nutter, E. Schneider, S.P. Swordy, G. Tarlé, A. D. Tomasch, E. Torbet. Astropart. Phys. 11, 429, 1999.
- Cosmic Ray Electrons and Positrons. D. Müller. Adv. in Space Res. (2001, in press).
- Cosmic Rays beyond the Knee. D. Müller. In The Astrophysics of Galactic Cosmic Rays, Kluwer, 2001 (in press).
Ph.D., Karlsruhe, 1993.
Professor, Dept. of Physics, Dept. of Astron. & Astro., Enrico Fermi Institute, Kavli Institute for Cosmological Physics, and the College.
Experimental physics, ultra-high-energy cosmic rays.
The origin of Ultra-High Energy Cosmic Rays (UHECRs, >1019 eV) is a fascinating long-lasting mystery of particle astrophysics. What physical mechanism can produce or accelerate particles to energies 10 billion times higher than the man-made LHC beam? Whether the answer is to be found in the most extreme objects of the universe (e.g. Active Galactic Nuclei powered by blackholes) or in exotic new fundamental particle physics (e.g. cosmological strings), our view of the energy frontier in particle astrophysics will be challenged. To detect these rare particles, the Pierre Auger Observatory covers 3000 km2 in the province of Mendoza, Argentina - the largest cosmic ray detector ever built. Privitera has given major contributions to the design, construction and data analysis of the Fluorescence Detector, which measures the fluorescence light from the nitrogen molecules excited by the cosmic ray shower particles along their path in the atmosphere. Privitera also led the AIRFLY experiment to the most accurate measurement of the nitrogen fluorescence yield and its pressure, temperature and humidity dependence. Currently, Privitera’s group is pushing next generation UHECRs detectors, by exploring the potential of microwave emission from the cosmic ray shower, and developing a compact Fluorescence Detector. In addition, the group is preparing for a major upgrade of the Auger Observatory, which will include a giant array of scintillator detectors.
The nature of Dark Matter - five times more common in the universe than ordinary matter according to astrophysical and cosmological evidence – is still eluding our understanding. A compelling hypothesis invokes yet unknown Weakly Interacting Massive Particles (WIMPs) as a major component of Dark Matter. Privitera is searching for WIMPs with the DAMIC (Dark Matter In CCDs) experiment at the SNOLAB underground laboratory in Sudbury, Canada. DAMIC employs mm-thick CCDs of unprecedented low energy threshold (few tens of eV) to detect nuclear recoils from low mass WIMPs. Privitera’s group plays a major role in the experiment, now undergoing installation of a 100 g detector which will probe a large, so far unconstrained range of WIMP masses and interaction cross- sections. Privitera is also performing measurements of the nuclear recoil ionization efficiency in silicon down to sub-keV energy, essential for a proper interpretation of WIMP limits.
As an experimental particle physicist, Privitera worked for the DELPHI experiment at the LEP e+ e- collider (CERN, Geneva), with main contributions in the measurement of the properties of the Z and W bosons, in the physics of the τ lepton and of the b quark.
- "The Microwave Air Yield Beam Experiment (MAYBE): measurement of GHz radiation for Ultra-High Energy Cosmic Rays detection", arXiv:1108.6321 (Aug 2011)
- "The Pierre Auger Observatory I: The Cosmic Ray Energy Spectrum and Related Measurements", arXiv:1107.4809 (Jul 2011)
- "The Pierre Auger Observatory V: Enhancements", arXiv:1107.4807 (Jul 2011)
- "The Pierre Auger Observatory IV: Operation and Monitoring", arXiv:1107.4806 (Jul 2011)
- "The Pierre Auger Observatory III: Other Astrophysical Observations", arXiv:1107.4805 (Jul 2011)
- "The Pierre Auger Observatory II: Studies of Cosmic Ray Composition and Hadronic Interaction models", arXiv:1107.4804 (Jul 2011)
- "Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory", arXiv:1106.3048 (Jun 2011)
- "Advanced functionality for radio analysis in the Offline software framework of the Pierre Auger Observatory", Nuclear Instruments and Methods in Physics Research Section A, Volume 635, Issue 1, p. 92-102 (Apr 2011)
- "Search for first harmonic modulation in the right ascension distribution of cosmic rays detected at the Pierre Auger Observatory", Astroparticle Physics, Volume 34, Issue 8, p. 627-639 (Mar 2011)
- "The exposure of the hybrid detector of the Pierre Auger Observatory", Astroparticle Physics, Volume 34, Issue 6, p. 368-381 (Jan 2011)
Ph.D., UCLA 2010
Assistant Professor, Dept. of Physics,Enrico Fermi Institute, Kavli institute of Cosmological Physics, and the College
Cosmic Microwave Background, Cosmology, Particle Astrophysics, and Neutrino Physics
Abby's research is focused on experimentally investigating some of the most fundamental questions about the nature of our Universe. Her research ranges from the study of the extremely early universe to probing our understanding of particle physics and astrophysics at extremely high energies.
Abby works on a series of polarimeters at the South Pole (BICEP2, The Keck Array, and BICEP3) that aim to directly probe the epoch of Inflation in the very early universe by measuring the unique polarization signature which would have been imprinted on the Cosmic Microwave Background by the Inflationary Cosmic Gravitational-Wave Background.
Abby also works on experiments that search for ultra-high energy neutrinos (E~1018 eV) using radio detection techniques. She works on ANITA, a balloon-borne telescope that was designed to search for coherent radio emission produced by the interaction of UHE neutrinos with Antarctic ice and by UHE cosmic rays that induce showers in the atmosphere. She is also working on a new detector, the Greenland Neutrino Observatory (GNO) that will look for ultra-high energy neutrinos from a ground-based array at Summit Station in Greenland.
Ph.D., University of Minnesota, 1999.
Assoc. Prof., Dept. of Physics, Enrico Fermi Institute, and the College.
Experimental physics, particle astrophysics, high-energy astrophysics.
My research spans a number of topics in the categories of experimental astroparticle physics and high-energy astrophysics. This includes several investigations into the nature and origin of very high energy (VHE) cosmic radiation, including gamma rays above 10 GeV and cosmic rays above 100 TeV. I am also interested in topics at the interface of cosmology and astroparticle physics, including studies of the propagation of VHE gamma rays through extragalactic photon fields. I currently am working on the following projects:
VERITAS - the Very Energetic Radiation Imaging Telescope Array System. This experiment comprises 4 12-meter imaging atmospheric Cerenkov telescopes designed to detect and measure gamma rays over an energy range of ~50 GeV to 50 TeV. VERITAS is the most sensitive instrument of its kind in the northern hemisphere for the investigation of gamma ray sources such as galactic supernova remnants and AGN.
CTA – the Cerenkov Telescope Array. CTA is a world-wide collaboration to build the next generation of ground-based gamma-ray observatory. CTA builds on the success of VERITAS, HESS, and MAGIC, and aims to achieve a sensitivity which is 10 times better than the best of current instruments. CTA is currently in an R&D phase, with construction expected to begin within 5 years.
CREST - the Cosmic-Ray Electron Synchrotron Telescope. The CREST experiment is a high-altitude balloon payload designed to measure the flux of cosmic-ray electrons at energies above 2 TeV. CREST uses a novel, never previously demonstrated, technique which depends on the detection of the synchrotron photons generated by the electrons in the earth’s magnetic field. CREST is scheduled to fly in Antarctica at the end of 2011.
- Discovery of TeV Gamma Ray Emission from Tycho's Supernova Remnant, The VERITAS Collaboration, to appear in ApJL (2011).
- A connection between star formation activity and cosmic rays in the starburst galaxy M82, the VERITAS Collaboration, Nature 462, 770 (2009).
- Detection of Extended VHE Gamma Ray Emission from G106.3+2.7 with VERITAS., The VERITAS Collaboration, ApJL 707, 612 (2009).
- VERITAS Observations of the _-Ray Binary LS I +61 303, The VERITAS Collaboration, ApJ 679, 1427 (2008).
- Measurements of cosmic-ray secondary nuclei at high energies with the first flight of the CREAM balloon-borne experiment, The CREAM Collaboration, APh 30, 133 (2008).