Understanding the Origin of the Hubble Sequence of Galaxies

California Institute Of Technology, Pasadena CA

Investigators

Abstract

AST-0307859 Ellis This program will support the collation of new ground-based data for large samples of galaxies observed at various redshifts and look-back times with the goal of developing a self-consistent observational story of how galaxies evolve and assemble to produce the diversity of morphologies seen today. The way forward focuses on determining the underlying mass of an evolving galaxy, both from internal dynamics via ultra-deep Keck 10m spectroscopy and from deep infrared photometry with the Palomar 5m telescope. This is a self-contained data set, which will be used to trace the growth rate of distant galaxies and the movement of galaxies from one morphological category to another. It is also a valuable addition to the DEEP2 redshift survey already being conducted (with partial NSF support) by Caltech and University of California colleagues. The team has unrivalled access to the necessary telescopes and instrumentation, and will produce an integrated picture of morphological evolution and assembly history, based on a sample a hundred times larger than any currently available. The research includes graduate and undergraduate student training, useful spin-off in the form of techniques for other researchers to use in their data analysis, and will be intimately linked with a new public outreach program at Caltech entitled Unravelling Cosmic History with Large Telescopes. ***