Members of the the extragalactic group work on a broad array of astrophysical
questions: What is the expansion history of the Universe and the evolution of
dark energy? How do cosmic structures form and evolve?
Which objects reionized the Universe and how did they do it?
When did the first galaxies form and what what were their properties?
How does the baryonic content of galaxies grow and what is the relative
importance of different processes, such as major mergers, minor
mergers, smooth cold mode accretion, and secular processes?
Through what feedback processes are baryons cycled out of galaxies?
How do black holes form, grow and impact their host galaxies and surroundings?
Where are we with regards to long-standing challenges for Lambda cold dark
matter models of galaxy evolution, such as the angular momentum problem, the
challenge of bulgeless galaxies, the sub-structure problem, and the cusp-core
controversy? How do galaxies evolve both in time and in different
environments, such as field, groups, and clusters? Research areas include:
Group members tackle these problems both through state-of-the-art simulations
using for instance, the Texas Advanced Computing Center (TACC) and panchromatic ground and space observations
from X-ray to radio wavelengths. We are involved in several large
imaging and spectroscopic survey of galaxies, including:
HETDEX (Hobby-Eberly Telescope Dark Energy Experiment)
GEMS (Galaxy Evolution from Morphology and SEDs)
GOODS (Great Observatories Origins Deep Survey)
GOODS-NICMOS Survey (GNS) of Massive Galaxies
STAGES (Space Telescope A901/902 Galaxy Evolution Survey)
Coma Cluster ACS Treasury Survey
VENGA (The VIRUS-P Exploration of Nearby Galaxies)
VIXENS (The VIRUS-P Investigation of the eXtreme ENvironments of Starbursts)
Director McDonald Observatory
Dwarf spheroidal galaxies, stellar populations in the Galaxy and nearby galaxies, globular clusters, and astronomical instrumentation.