Formation and Evolution of E and S0 Galaxies from HST and Keck Studies of z 0.3-1 Clusters
Source: Astrophysics and Space Science, Volumes 269-270, 1999 , pp. 485-492(8)
We have witnessed a dramatic increase over the last five years in results on distant galaxies, in large part because of the high resolution imaging capability of HST, and the multiobject spectroscopic capability of the Keck telescopes. Our program to obtain wide-field, multi-color WFPC2 mosaics with HST of intermediate redshift clusters, and spectroscopic membership and high S/N spectroscopy with LRIS on Keck, has provided new insights into the nature of elliptical and S0 galaxies in the cluster environment over a wide range of densities. In particular, most ellipticals, and a significant fraction of the S0 population, have large luminosity-weighted ages, suggesting that their stellar populations were formed at redshifts beyond z 2, though the existence of substantial numbers of major mergers in MS 105403 at z =0.83 suggests that final assembly of such galaxies may not have occurred until much later for a significant fraction of early-type galaxies.
Document Type: Regular paper
Affiliations: 1: UCO/Lick Observatory, Astronomy and Astrophysics Department, University of California, Santa Cruz, CA 95064, USA 2: Department of Terrestrial Magnetism, 5241 Broad Branch Road, NW, Washington DC 20015, USA 3: Leiden Observatory, P.O. Box 9513, 2300 RA Leiden, The Netherlands
Publication date: 1999-01-01