The astrophysics group at
The observers and theorists in the group interact closely,
and many recent student theses have included both theoretical and observational
projects. Most theoretical research is heavily computational, and dynamics
often involves N-body simulations. There are also links to the
particle-astrophysics interests of the
Our observations are carried out in all regions of the spectrum, including
X-ray, ultraviolet, optical, and radio wavelengths. Data are obtained using
both ground-based telescopes and space observatories. The imaging Fabry-Perot
interferometer resides at the Cerro-Tololo Inter-American Observatory in
Graduate students who intend to carry out thesis work in astrophysics are encouraged to follow the astronomy option, which allows them to replace several of their upper division course requirements with astrophysics courses.
Professor Andrew Baker
I study the evolution of galaxies, both as individuals and as populations, using observations of the nearby and distant universe. I make regular use of data acquired at multiple wavelengths from the ultraviolet through the radio, but I focus on the (sub)millimeter bands where we can observer continuum emission from dust grains and rotational line emission from small molecules. These tracers allow us to study the most optically obscured (and often the most interesting!) regions of the galaxies. Some current questions of interest: How do extreme environmental conditions affect the process of star formation? What are the demographics, properties, and evolutionary states of dusty, high-redshift “submillimeter galaxies”? How can we use observations to test the assumptions and predictions of galaxy evolution models that are based on the cold dark matter paradigm for structure formation?
Professor Thomas Devlin
I am working with students on projects directed at studying the large-scale
structure of the universe. We are analyzing
data we collected with the fully-steerable 100-meter radio telescope in
Greenbank, W.Va., to measure the polarization of 43 GHz radiation from
galaxies. This is a potential foreground source which must be understood to
correct future measurements of polarization in Cosmic Microwave Background
(CMB). We have also built equipment for
the multi-university collaboration building ACT, a 6-meter microwave telescope
to be operated on the Atacama Plateau in
Professor John P. Hughes
I study the X-ray properties and Sunyaev-Zel'dovich effect of clusters of galaxies in order to measure the expansion factor of the Universe, the so-called Hubble constant. This research also aims at understanding the origin, evolution, and nature of these systems, which are the largest dynamically organized structures known. My research interests also include observational and theoretical studies of supernova remnants as probes of stellar and explosive nucleosynthesis, the nature of the interstellar medium, the physics of supersonic shock waves, and the formation and evolution of instabilities in supernova ejecta. I also am involved in the planning and development of new X-ray satellite missions including AXAF and Astro-E.
Professor Charles Joseph
My research interests include the interstellar medium, studies of the origin and evolution of galaxies, and technology development for optical/ultraviolet space instrumentation. I will be collecting and analyzing data taken with the Primary-Focus Instrument on the SALT telescope, which will be commissioned in November 2005. New technology initiatives include the development of ultraviolet detectors made of III-Nitrides, which offer significant performance improvements over existing UV image sensors. I and a team of internationally recognized astronomers will be proposing to NASA to build, fly, and operate a series of long-duration balloon flights. The balloon-borne telescope will have a floatation altitude of 35 km (19 miles) and will provide spatial resolutions comparable to the Hubble Space Telescope. Typical flights are expected to last 2-3 weeks and be flown once per year. We will use this series of balloon missions to perform detailed velocity maps over wide fields of view to determine the formation and evolution of galaxies.
Professor Charles Keeton
I use gravitational lensing to study galaxies and cosmology. Strong lens systems provide the only direct probe of dark matter distributions on subgalactic scales, and therefore provide crucial constraints on the fundamental nature of dark matter. The connection between lenses and their environments offers clues about the processes that drive galaxy evolution. Lenses act as natural telescopes that help us to resolve the internal structure of quasars. They are beginning to let us measure supermassive black holes in distant galaxies. In the future, lensing will provide precise tests of general relativity and alternative gravity theories. My work involves a broad array of research methods, from observations (including HST and SALT) to data modeling to numerical theory to formal mathematics.
Professor Terry Matilsky
Most recently, I have become interested in fundamental theories of gravitation. It appears that all of the standard "dark matter" scenarios are significantly flawed, and recent work in string theory has pointed us toward modification of our current ideas concerning gravitational dynamics. I have examined a new idea that postulates an additional interaction in four spatial dimensions that has the potential to solve the dark matter problem, as well as address some fundamental questions in both cosmology and high-energy physics. The most up-to-date paper concerning this can be found at: by clicking on "gravity".
Professor Carlton Pryor
My research interests are centered on observational and theoretical studies
of the structure and evolution of both star clusters and individual galaxies. I
am currently surveying the kinematics, mass distributions, and stellar contents
of the dense centers of globular star clusters, the oldest clusters in our
Galaxy. With the Rutgers Imaging Fabry-Perot Spectrometer in
Professor Jerry Sellwood
My main interest is in the formation and evolution of galaxies. In particular, I try to understand the dynamics of these large stellar systems and to determine the amount and distribution of Dark Matter within them. My findings is challenge predictions from the current Cold Dark Matter model of the universe. Other interests include such questions as: What causes the graceful spiral patterns seen in most disc galaxies? And why do many, but not all, have bars? Although analytical methods can be used to some extent, I find that the most fruitful line of attack on these questions is through large N-body simulations.
Professor Ted Williams
My interests include optical observations of extragalactic objects and instrument development. One current project involves the measurement of the kinematics of both stars and gas in barred spiral galaxies, in order to determine the structure and dynamics of these galaxies. Other active research involves measuring the velocities of stars in the dense cores of globular clusters, detecting and measuring the velocities of planetary nebula surrounding elliptical galaxies, and refining the Tully-Fisher technique for measuring the distances to galaxies.
Professor Harry Zapolsky
I am currently studying the physics of gravitational collapse. My interest is specifically in astrophysical systems (young globular clusters and elliptical galaxies) in which the dynamics of the constituent stars is essentially collisionless, so that the system is not constrained to evolve towards the Boltzmann distribution. Questions of fundamental physical significance include the nature and uniqueness of the ultimate steady state distribution produced by "violent relaxation" during the collapse, and how such systems manage to acquire (approximate) constants of motion.
Revised July, 2005