Neal Katz, University of Massachusetts
Katz has worked extensively in the field of numerical simulation in astrophysics. With Hernquist he developed TreeSPH, a program to evolve three dimensional self gravitating fluids that uses a tree algorithm to calculate gravitational forces and smoothed particle hydrodynamics (SPH) to calculate gas properties. With Quinn he has developed TIPSY (Theoretical Image Processing SYstem), an interactive, graphical program for the analysis of astrophysical simulations, allowing ``observations'' of the optical, X-ray luminosity and spectra, absorption lines and HI maps, for comparison with real observations. He has also authored ``The N-body Constitution", an attempt to place quality controls on the numerous N-body simulations performed today.
Eric V. Linder, University of Massachusetts
Linder's main expertise is in cosmology and science education. He has published First Principles of Cosmology (Addison-Wesley 1997), an introductory textbook on the level of advanced undergraduates to beginning graduate students, and has served as scientific consultant to award winning science writer Timothy Ferris' cosmology popularization, The Whole Shebang: A State of the Universe(s) Report (Simon & Schuster 1997). His research addresses the cosmic background radiation, gravitational lensing, the early universe, and the influence of structure on cosmological distance relations. He has also worked on teaching the art of physical interpretation of numerical results, emphasizing awareness of physical assumptions, approximations, and scalings.
Martin Weinberg, University of Massachusetts
Over the last 10 years, Weinberg's work has centered on the structure and long-term evolution of galaxies and the dynamics of stellar systems. He has pioneered computational solutions and astrophysical applications of the perturbed Boltzmann equation. Recently, he has developed computational statistical techniques for inferring the global structure of the Galaxy from star count data from large-scale surveys and is a member of the 2MASS Science Team. Currently, Weinberg is engaged in an extensive exploration of halo-disk-environment interactions using both modal analyses and N-body techniques. Ongoing work also includes study of the dynamics of star clusters and dwarf galaxies in tidal fields, multi-body encounters in globular clusters, and statistical comparison of dynamical theories to cluster observations.
Lars Hernquist, Harvard University
Hernquist has been active in the field of numerical astrophysics for more than a decade. With Katz and later D. Weinberg, he developed TreeSPH and generalized it to include the non-gravitational processes needed for modeling the formation of galaxies and large-scale structures in a cosmological context (e.g. radiation physics and star formation). This code has been used extensively by us to study the origin of quasar absorption lines and galaxy statistics in a variety of cosmological models. Hernquist has also optimized various types of N-body methods for supercomputing architectures, such as the hierarchical tree and self-consistent field algorithms, and has used these codes to study tidal disruption, the dispersal of tidal debris, the growth of black holes in galactic nuclei, and the structure of the remnants of galaxy mergers.
Thomas Quinn, University of Washington
Quinn's research interests are on applications of numerical dynamics to various systems covering an enormous range of scales: from the Solar System to the large scale structure of the Universe. His work on the Solar System has included the origin of Oort cloud and short period comets, confirming the chaotic nature of the orbits of terrestrial planets, and predicting the existence of the Kuiper belt. With J. Stadel, he has developed an adaptive cosmological N-body code capable of running efficiently on massively parallel computers. With this code he has created cosmological simulations with the highest dynamic range to date: simulations of (1000 Mpc)3 with a force resolution of 100 kpc.
David H. Weinberg, Ohio State University
Weinberg has used cosmological N-body simulations to model the formation of large scale structure in different cosmological scenarios and to guide the development of statistical methods for testing theoretical models against galaxy redshift survey data. He has worked with Katz and Hernquist on the extension of TreeSPH to include photoionization and star formation and on the application of TreeSPH to the study of galaxy formation, the intergalactic medium, and QSO absorption lines. He has also lectured on cosmological simulation methods and the physics of the intergalactic medium at the Jerusalem Winter School in Theoretical Physics and is a member of the Sloan Digital Sky Survey collaboration.