SEMINAR
CANCELLED!
Dr. James Schombert
Title: The Evolution of
Cluster Populations
This is an
ongoing project to study the photometric and morphological properties of low
and intermediate redshift cluster populations. Using
a unique narrow band filter system, we examine the colors of cluster galaxies
to follow the Butcher-Oemler effect, the red envelope
and the color-magnitude diagram with lookback
time. Combining this data with HST imaging allows us to compare the photometric
properties of cluster galaxies with their morphological and structural
properties. We find that the fraction of blue galaxies increases
with decreasing luminosity in a cluster (a dwarf starburst population) and that
the number of bulge+disk S0's decreases from a redshift of 0.3 suggesting that they are converted to ellipticals by cluster dynamical processes. Higher
precision photometry will allow us to estimate the age and metallicity
of the red population in clusters, and compare this
sample to nearby field galaxies, a key test to hierarchical galaxy formation
scenarios.