In the last several years, I have worked intensively on the supermassive star
Eta Carina, which in its great eruption 160 years ago, ejected an enormous mass
(10-20 times that of our sun) into space. In a short period of time,
astronomically speaking, the star itself may finally die in a supernova explosion.
The Hubble Space Telescope (HST) has designated our study of Eta Carina as one of
its Treasury Projects, devoting large amounts of time to studying its variations.
I'm enthralled by dirt -- at least the astronomical kind. The dust out of which
our planet formed, originally came from the stars. For many years, I have
been studying the conditions under which this dust condenses out of hotter gases.
Novae, for example, are stars that undergo non-fatal explosions that expel enormous
amounts of dust into space. I have played major roles in the decades-long
planning and development of the Spitzer Infrared Telescope, now bringing us
spectacular images of our dusty space environment. I am looking forward to using
the infrared-optimized LBT to study dust in interesting systems such as the RY
Scuti binary system, with two stars orbiting each other so closely that they touch.
My research spans the structure of our Milky Way to the study of the populations
of massive stars here and in nearby galaxies. I use our own in-house database
of a 100 million objects to map the structure of our galaxy and observations with
the Steward telescopes to study the "supernova imposters," which are very massive
stars expelling large amounts of matter into space.
I am an infrared astronomer who specializes in measuring the polarization of
light. This type of observation can reveal the structure of dust in comets,
the magnetic field geometry in galaxies and pinpoint the location of hidden
stars. Specialized observing procedures are required, but a few major
facilities such as the NASA IRTF and the Hubble Space Telescope have a
polarimetric capability I am able to use. We are building a precision infrared
imaging polarimeter for use on the MMT in combination with the AO secondary.
I do research in theoretical and computational astrophysics, mainly
addressing problems associated with very energetic phenomena and their
impact on the universe. My students and I carry out large fluid dynamical
simulations including specially developed routines to follow the microphysics
responsible for the emission we observe from such astronomical objects as
supernova remnants, active galaxies and clusters of galaxies.
Our calculations can be compared directly with observational data
to test basic theories about the origins of these objects.
I'm interested in the extremely high energy particles generated in shock waves,
both in giant clusters of galaxies on scales up to millions of light years, and
in the smaller explosions of dying stars, as they create supernova remnants. I
study these systems using radio, optical, X-ray and infrared images and spectra
from both ground- and space-based telescopes.
Understanding how galaxies are formed and evolve presents arguably the biggest
challenge for astrophysics in the next decade. As new observing facilities
come on-line, we can look back to the earliest ages of our universe and
learn more about galaxies in their infancy. I am currently conducting a parallel
approach by studying the nearest dwarf galaxies which are the most numerous
galaxies in the Universe and the likely building blocks of all galaxies. Like
an archaeologist, I reconstruct their lives by exploring the
fossil records by measuring the ages, metallicities, and distributions of their
oldest stars.
I am interested in the distribution of "dark matter" in the Universe, on scales
ranging from sub-galactic to those larger than clusters of galaxies. Dark matter
is the dominant matter component in the Universe, yet its nature has eluded us
so far. I study gravitational lensing of high redshift sources, and dynamics
of individual galaxies and clusters, to gain detailed knowledge of the clustering
properties of dark matter.
One focus of my current research is the study of solar system comets, which are
frozen reservoirs of primitive solar dust grains and ices. I analyze the
composition and size distribution of cometary dust grains from infrared imaging
and polarimetry techniques using the LBT and Steward Observatory telescopes which
support my Spitzer Infrared Telescope activities. In this way, I can determine the
physical characteristics of the solid materials that constituted the primitive solar
nebula, out of which planetesimals, then planets, and eventually we, ourselves,
were formed.
Deep inside a star, the churning and the transfer of massive amounts of energy
are not open to direct observation. However, through the use of sophisticated
physical models and numerical simulations on supercomputers, we can investigate
how these invisible processes work. Recently, we have been concentrating on the
convection processes in stars near the end of their red giant phases.
Our observational colleagues can search for the subtle signatures of these processes,
and improve our understanding of the hidden interiors of stars.
Profile: Danielle Berg
I am a first year graduate student. I did my undergraduate in physics and mathematics at Gustavus Adolphus College and am now interested in studying the distribution of dark matter and its properties and AGN.
Profile: Shea Brown
It is predicted that a large fraction of the total baryons in the universe
reside outside the well studied dense clusters of galaxies. Cosmological
simulations show a universe where rich clusters and super-clusters of
galaxies are connected by a diffuse "cosmic web" of sheets and filaments,
but these regions are difficult to detect precisely because they are such
low density environments. My research, in collaboration with Prof. Larry
Rudnick, focuses on using non-thermal emission to detect and characterize
these low density regions, using powerful telescopes such as the Very
Large Array, the Greenbank Telescope, and the Westerbork Synthesis Radio
Telescope array. Our current focus is on using polarization observations
to detect very low surface brightness emission purportedly cause by shocks
related to large scale structure formation.
Profile: Jennifer Delgado
I am second year graduate student working for Chick Woodward. I use Spitzer IRAC subarray data to try to find young stellar objects in the Hourglass region of Messier 8. I am also interested in the theoretical side of star formation.
Profile: Kathleen Dewahl
I am a first-year graduate student, with intrests in pre-main sequence stars and instrumentation. As an undergrad I worked with T-Tauri type stars, trying to identify and observe possible FU-Orionis candidates.
Profile: Paul Edmon
I am a graduate student working for Tom Jones. I do numerical simulations of particle acceleration at astrophysical shocks. More specifically stellar winds and supernova remnants. Using efficient numerical schemes for Magnetohydrodynamics and Cosmic Ray acceleration we model both the dynamics and emissions from these objects and compare them to what is actually observed. These comparisions help us verify our theory for particle acceleration and understand how these interesting objects work.
Profile: Damon Farnsworth
I am a research assistant working under Professor Larry Rudnick, currently investigating galaxy cluster radio relics and their role as tracers of the large scale filamentary structure of the Universe. I also investigate the inside of my eyelids sometimes, and the role food (or lack thereof) plays in my level of grumpiness.
Profile: Andrew Helton
I am a graduate student working under the direction of Chick Woodward and Bob Gehrz. My research primarily involves the evolution of classical and recurrent novae using data obtained with the
Spitzer Space Telescope and multiple ground based observatories including Gemini, IRTF and our own Mt. Lemmon Observatory. Ultimately, these observations should provide further insight into the physical processes involved in novae outbursts, the dynamics of the ejecta, the formation and evolution of dust, and how the ejected material interacts with the interstellar medium and contributes to local chemical enrichment.
I am a graduate student currently working with Prof. Larry Rudnick on the
supernova remnant Cassiopeia A. I am most interested in medium and large
scale X-Ray variability using data from the Chandra X-Ray Observatory.
One aspect of my research is to observe detailed changes in the spectrum
of Cassiopeia A. This can give us information about how Cassiopeia A's
shocks interact with the ejecta from the supernova. I also supplement the
X-Ray data with IR data from the Spitzer Space Telescope in order to
further study radiative processes in this interesting astronomical object.
Profile: Kristy McQuinn
I am a 5th year graduate student working with Dr. Evan Skillman to
determine the duration of starbursts in nearby dwarf galaxies. A starburst
is an episode of intense star formation in a galaxy that affects not only
the structure and evolution of the host galaxy but also the chemical
composition of the galaxy's external environment (the intergalacitc
medium). Understanding how long a starburst lasts requires a
reconstruction of the galaxy's recent star formation history. The duration
is an important and fundamental parameter in the study of starbursts
because it affects much of the subsequent analysis and study of a
starburst galaxy's evolution. Our work uses optical images from the Hubble
Space Telescope of more than a dozen nearby dwarf systems and stellar
evolution models to determine the rate of star formation over the past 1
billion years.
Profile: Andrea Mehner
I studied physics at the FSU Jena, Germany, with a focus in astrophysics and geophysics. I completed my diploma thesis at the TLS Tautenburg working on the multiplicity of ultra-cool objects and the atmospheres of brown dwarfs.
I am a graduate student working under the supervision of Tom Jones in the computational astrophysics group. My current research utilizes high resolution simulations of radio jets to investigate the observational consequences of their interactions with the ICM. By including relativistic electron transport in the simulation, we have calculated synthetic radio and x-ray observations of these jets. Knowing the details of the physics in our simulations, observed properties can be directly related with physical quantities.
I am a member of the
observational
cosmology group working for Shaul Hanany to help fly the next
generation of balloon-borne cosmic microwave background experiments. We
hope to measure the polarization of the background radiation, which will
yield better values for cosmological parameters, and should constrain
inflationary models of the big bang. My current work deals principally
with designing the optical systems to be used in these experiments,
relying heavily on physical optics modeling to analyze optical
performance.
Profile: Dan Polsgrove
I'm a graduate student working on the E and B Experiment (EBEX) in the
observational cosmology group for Terry Jones and Shaul Hanany. EBEX is a
telescope designed to probe the polarization of the cosmic microwave
background while floating at 120,000 ft altitude suspended underneath a
giant helium balloon. Data collected during a future 2-week flight over
Antarctica should reveal new and interesting details about the early
universe. I've designed and built several ground-based calibration
experiments that will be used to characterize the instrument's
polarization and spectral response. I am also generating simulations and
plans for in-flight calibration that will be executed during a 1-day test
flight over New Mexico.
Profile: Tea Temim
I am a second year graduate student working with Prof. Chick Woodward in the
infrared astronomy lab. My current research involves the study of the famous
Crab nebula and N49, a young supernova remnant in the LMC that is
interacting with a massive dense molecular cloud. I use infrared images from
the Spitzer space telescope along with images at other wavelengths to try to
understand the composition, physical conditions, and the complex morphology
of these supernova remnants.
Profile: Chelsea Tiffany
I'm a first year grad student. During undergrad I worked on velocity
relationships in binary start systems, analyzing data for a pulsar and
looking at the interaction of solar winds with the Earth's magnetic
fields. I attended Wellesley College outside of Boston.
Profile: Tom Vonderharr
I'm a first year graduate student. I received my BS in Physics degree at Truman State University in Missouri and am glad to again be living in a more populous human settlement... For research I'm interested in stellar formation and evolution as well as the planetary science that goes along with it, but right now it's all about taking classes.
Profile: Steve Warren
I am working under the direction of Dr. Juergen Ott of Caltech and Dr. Evan Skillman as a member of the VLA-ANGST team which is a part of the larger ANGST project. We are using the VLA to study the HI gas in 36 dwarf galaxies. Each galaxy was observed in three different array configurations (B, C, and D) to give us a sensitivity of ~6". We are currently in the data reduction process, but will soon look into the details of star formation histories and stellar feedback into the ISM for each galaxy.
I am in my third year of graduate school working with Evan Skillman.
I primarily study star formation and its role in the evolution of
galaxies. Specifically, I use Hubble Space Telescope images of dwarf
galaxies to reconstruct their star formation histories. Because
dwarf galaxies are the building blocks of larger structures in the
universe, the history of their star formation allows us to trace
galaxy evolution from early proto-galaxies all the way to massive
spirals. Along these lines, I am interested in both ancient star
formation (e.g. the role of cosmic reionization and star formation in
the early universe) and recent star formation (e.g. understanding how
regions of star formation propagate throughout a galaxy).