University
of California, Davis
Physics
Department
Cosmology
Seminar
" Post-Starburst Galaxies at Intermediate
Redshifts"
<>We isolate post-starburst (E+A) galaxies at intermediate redshifts (0.3<z<1) to understand how star-forming galaxies evolve into passive, early-type systems in both the cluster and field environment. We find E+A's make up a significant fraction (~11%) of the cluster galaxy population at z>0.3, and that >30% of early-type members have undergone an E+A phase by z~0. We also find evidence in clusters of a decreasing characteristic E+A mass with redshift, similar to the <>decrease in luminosity of rapidly star-forming field galaxies since z~1 (``down-sizing''). In comparison, only ~3% of field galaxies at <>intermediate redshifts are E+A's. Although the E+A fraction in the field is lower than in clusters, the E+A phase is still an important <>link between emission line galaxies and absorption line systems in this environment: we estimate that ~25% of passive galaxies in the localfield had an E+A phase at z<1.
Thursday,
May 13, 2004
12:10 p.m., 416 PHY/GEO