Eric Hallman

Simulating the Universe: Large Area Galaxy Cluster Surveys and Synthetic Observing Tools
Contact information:
Institute for Theory and Computation
Harvard-Smithsonian Center for Astrophysics
60 Garden Street, MS-51
Cambridge, MA 02138
Fellowship status:
Starting year: 2007
AAPF alumnus
Fellowship institution: University of Colorado
Current (or last known) position: Research Scientist, Tech-X Corporation
Research Interests:

I am currently studying clusters of galaxies with numerical
simulations. There are a variety of interesting problems one can
explore using clusters. In my case, I have a particular focus on
understanding observations of the intracluster medium (ICM), a
diffuse, hot, X-ray emitting component of clusters which contains the
bulk of the baryonic material. From the simulation side, these objects
are modeled using sophisticated N-body/hydro simulation
codes. My focus has been on direct comparison of the simulations to
observations. Additionally, I have continued to work on X-ray observations of
clusters of galaxies from the Chandra and ROSAT X-ray telescopes, and
have begun to work directly with observers and instrumentalists on
Sunyaev-Zeldovich effect (SZE) observations of the cluster ICM. In
particular, a recent thrust of my research has been constructing very
large simulated sky surveys in X-rays and through the SZE. In this
way, we can identify the systematic effects in peforming precision
cosmological analyses using large area galaxy cluster surveys.

Education and Outreach Interests:

The driving idea behind the education and outreach plan is
two-fold. First, it is well known that the combination of the human
eye and brain is a superior set of tools for visual correlation. Second, people have a general intuition for fluid dynamics from their abundant
experiences with air and water. Combining these two natural human
abilities in order to gain physical intuition about cosmology and
astrophysics is the underlying goal of this project. At its simplest
level, animations of complex numerical simulations of astrophysical
objects can be used to enhance the student's understanding of
physics. This concept is not new, indeed it underlies the use of
laboratory demonstrations and animations of all sorts of physical
phenomena. The unique features here are that I will use numerical
simulations performed by myself and others to illustrate specific,
typically poorly understood, astrophysical concepts for use with
students of skill levels ranging from introductory to advanced,
spanning a continuum of very qualitative to very quantitative
approaches to the data.