February 19, 1998 CfA Colloquium


Title: Hubble Space Telescope Imaging of Distant Galaxies

Speaker: Richard Ellis

Abstract: The successful restoration of the imaging capabilities of Hubble Space Telescope has led to a revolution in our understanding of the way in which galaxies evolve. Observational progress has come from deep imaging in clusters of galaxies and in randomly-selected fields for which systematic ground-based redshift surveys have been undertaken. The results reveal a complex interplay between morphology and star-formation history and indicate that a significant fraction of massive galaxies completed the bulk of their star formation at early times. However, a surprising amount of star formation has occurred more recently, particularly in less massive systems. These and other results will be discussed in the context of contemporary models accounting for the growth of structure. Observations with the new generation of large telescopes will give further insight into the physical processes responsible for the variety of galaxies seen today.

Reference for students: "The HDF: Intro and Motivation," Ellis, and "Evolution of Luminous Matter in the Universe," Madau.