Date/Time
Date(s) - 10/09/2003
3:30 pm - 4:30 pm

Title: Extreme Clusters in the Red-Sequence Cluster Survey

Speaker: Dr. Mike Gladders

Institute: The Observatories of the Carnegie Insitution of Washington

Location: ABB 102

Description:

The Red-Sequence Cluster Survey (RCS) is a ~100 square
degree imaging survey designed to locate and characterise
galaxy clusters to redshifts as high as 1.4. After a brief
description of the complete survey and some of the original
RCS results, I will focus the rest of this talk on recent
results coming primarily from 8m-class telescope followup of
the cluster sample. In particular, I will discuss two “extreme”
cluster subsamples: clusters with arcs due to strong lensing
of background sources, and clusters at very high redshifts.
The strong lensing clusters provide an unambiguous detection
of evolution in the RCS sample, and demonstrate that
a previously unrecognized sample of “super-lenses” must
exist. The high-redshift clusters are particularly powerful
for studying the formation epoch and formation process of
early-type galaxies; like previous smaller studies, the
RCS results indicate that the stars in early-type galaxies
formed early in the universe, though with a broader
spread in star formation histories than previously indicated.