Cosmology and Astrophysics

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Astrophysics/Cosmology Faculty

The Cosmology and Astrophysics Research Group at the University of Pittsburgh is a vibrant group of researchers working on a diverse array of topics, from stellar explosions to the physics of the early Universe. The group maintains a wiki page detailing past, present, and future research projects within the group. This page includes software tools created by the group as well as information for prospective students who would like to become involved with cosmology and astrophysics research at the University of Pittsburgh. A calendar summarizing important group activities is also available.





The faculty in the University of Pittsburgh Cosmology and Astrophysics group are Dan Boyanovsky, D. John Hillier, Arthur Kosowsky, Jeffrey A. Newman, Regina Schulte-Ladbeck, David Turnshek, Michael Wood-Vasey, and Andrew R. Zentner. Sandhya Rao, Jon Weisheit, and Jeffrey Winicour are members of our research faculty. Professor Emeritus E. (Ted) Newman continues active research in numerical General Relativity.





The group traditionally has been composed of independent investigators with diverse research interests and activities. Within the current group the main focus is on topics that impact observational and theoretical cosmology. Over the past ten years or so, significant activity in the group has involved observational studies of quasars and active galactic nuclei (Turnshek); quasar absorption lines and especially neutral gas systems (Rao, Schulte-Ladbeck, Turnshek); 21cm studies of galaxies (Rao); cosmic star-formation (Rao, Turnshek); gravitational lensing (Rao, Turnshek); stellar populations and element abundances in dwarf galaxies (Schulte-Ladbeck); and massive stars (Hillier, Schulte-Ladbeck). Computational and theoretical areas of interest have included cosmic microwave background (Kosowsky); early universe cosmology and neutrino astrophysics/cosmology (Boyanovsky); general relativity and quantum gravity (Newman); computational general relativity (Winicour); gravitational lensing (Newman, Turnshek); massive stars, supernovae, and quasars (Hillier, Weisheit); and high-energy-density plasmas (Weisheit).

Synopses of individual research programs

Boyanovsky conducts research touching on all three major research sectors within the department. His current research within the umbrella of astrophysics and cosmology focuses on neutrino cosmology and astrophysics, early universe cosmology, non-equilibrium aspects of ultra-relativistic heavy ion collisions, and the quark-gluon plasma. Over the past five years, Boyanovsky’s research program has shifted from the dynamics of quark-gluon plasma and the QCD phase transition towards inflation and neutrino cosmology/astrophysics.





Gatewood was the Director of the Allegheny Observatory prior to his retirement in June 2008. His research was directed toward trigonometric searches for planets, trigonometric parallax measurements, and the development of instrumentation for astrometry. During the last five years he has placed more emphasis on the development of CCDs for use in astrometry. Over the past 5-10 years his research has centered on extra-solar-system planet searches and studies, partly carried out in collaboration with the Carnegie Institution.





Hillier’s research interests include massive stars, one- and two-dimensional radiative transfer, supernovae, and QSO/AGN disk winds. In addition to improving diagnostic methods for understanding massive stars, his broad goals and activities now include developing an improved understanding of supernovae as standard candles and unified models of QSOs/AGN.





Kosowsky's research is broadly based in cosmology. His goals for the next five years are to develop theory and data analysis methods for ACT, particularly the SZ effect, gravitational lensing, and the primordial power spectrum. He also has interests in theory pertaining to inflation, the distribution of dark matter, and gravitational radiation.





Ezra Newman’s research is in the area of General Relativity. His current work primarily focuses on gravitational lensing, the structure of asymptotically flat space-times, and the differential equations that are equivalent to the vacuum Einstein equations. His work in gravitational lensing represents a change motivated by the availability of significant amounts of data. Due to the reduction of other demands on his time, Newman’s research has accelerated substantially since his retirement.





Rao’s research currently emphasizes programs that use QSO absorption lines to study the properties of the neutral gas component of the universe, with the goal of providing data to constrain models for galaxy formation. She has accomplished this through comprehensive HST-UV surveys for low-redshift (z<1.65) damped Ly-alpha (DLA) absorption lines. These have been very successful, resulting in the discovery of the large majority of low-redshift DLAs. She has also done follow-up work with optical ground-based telescopes in order to characterize the properties of the DLA absorbers (e.g., DLA host galaxy properties and neutral gas-phase metallicities).





Schulte-Ladbeck’s research is currently devoted to the study of star-forming galaxies, with the aim of studying them comprehensively through the use of both emission line and quasar absorption line techniques. This represents a change from her past areas of emphasis, which were observational studies of massive stars, with an emphasis on polarization studies, and studies of stellar populations in dwarf galaxies.





Turnshek’s research emphasizes observational studies of galaxy formation via QSO absorption-line techniques, QSOs/AGN, and strong gravitational lenses. Recently he has re-focused his efforts to achieve two goals with SDSS spectra. The first is to characterize results on the optical/UV spectra of QSOs in order to constrain QSO/AGN models; this is complementary to some of the work of Hillier. The second is to derive statistically large absorber samples for use in characterizing both the gaseous and stellar components of the universe; this is complementary to the work of Rao. Turnshek has also devoted a small fraction of his time to the development of Allegheny Observatory for student use and public outreach.





Weisheit’s research now is focused on quantum phenomena in high energy density plasmas, such as those occurring in inertial fusion experiments or compact astrophysical objects - white dwarfs and neutron stars. Current efforts include; (1) Understanding ionization balance in warm, dense matter and (2) developing conceptual models that enable some atomic processes to be included in large-scale classical molecular dynamics simulations of dense plasmas.






Winicour’s main area of research is the computation of gravitational waves emitted in the inspiral and merger of black holes. He plays a leading role in two international alliances that are dedicated to this problem. The first is the AppleswithApples alliance, which coordinates the validation of numerical relativity codes. The second is an alliance with the gravitational wave group at the Albert Einstein Institute in Potsdam to simulate the binary black hole problem. His change from active TTS faculty to research faculty has allowed him to devote more time to this research.





Zentner's research centers on the development of structure in dark matter cosmology, dynamical probes of dark matter, and models for the connection between visible matter and dark matter in the universe.

National and Local Facilities

National Telescope Facilities (NSF and NASA funded)








Group members make use of a number of national observing facilities, including NOAO and the public-access time it provides to private telescopes in the context of the US system of telescopes, the Hubble Space Telescope, and the Chandra X-ray Observatory.

















The Atacama Cosmology Telescope (ACT)








Pittsburgh became a member institution of the Atacama Cosmology Telescope project when Kosowsky joined the faculty in 2005. ACT is an NSF-funded project to map the microwave background in three frequency bands at arcminute resolution and unprecedented sensitivity. ACT is also organizing complementary astronomical observations in a range of wavebands, including radio, optical, infrared, and X-ray, providing a range of projects for undergraduate and graduate student participation. ACT is currently funded through the end of 2008. A number of local researchers, including Pitt students and Carnegie-Mellon faculty, have become involved with ACT theory and analysis.

















Sloan Digital Sky Survey (SDSS) (Participating Institution)








Pittsburgh became a Participating Institution in the Sloan Digital Sky Survey in 1999. Since then, Pittsburgh has contributed significantly to techniques for analyzing large astronomical data sets. For example, Pitt researchers have used SDSS data to study correlations between galaxies and quasars due to gravitational lensing, to measure the Integrated Sachs-Wolfe Effect by correlating the large-scale structure of galaxies with microwave background maps, and to study the properties of the neutral gas component of the universe. Rao, Schulte-Ladbeck, and Turnshek have made significant use of SDSS data, and new faculty member Zentner plans to continue to make use of SDSS. There is also significant use of SDSS by postdocs and graduate student researchers.

















Allegheny Observatory








The Allegheny Observatory, located 6 miles from our campus in Riverview Park, was founded in 1859 and moved to its current building in 1900. It houses the 30-inch Thaw refracting telescope and, until recently, the 31-inch Keeler reflector. Recently the Keeler telescope was replaced with an automated 16-inch telescope for student use. For the past three decades, Gatewood has served as Observatory Director and has maintained an active program of astrometric research; the Thaw refracting telescope remains one of the premier instruments for precision astrometry of bright stars. Due to its urban location, the range of competitive research which can be pursued from the Allegheny Observatory is limited. The University of Pittsburgh, in cooperation with the department, is developing plans to convert the Observatory to a science outreach facility. The Observatory currently provides observing and astronomy educational opportunities for thousands of students and the general public. In addition, it hosts a monthly science lecture series, weekly public tours and observing sessions, and an annual open house.