AAO Colloquium
Thursday 14 August 2003
3:30pm AAO Conference Room
The Evolution of Galaxies in High Redshift Clusters
Simon Ellis, AAO
The evolution of galaxies in clusters remains an area of
debate. The two most common explanations of massive, early-type galaxy
formation are those of monolithic collapse and hierarchical merging. In
the former galaxies form in a single burst of star formation whilst in the
latter case galaxies are assembled through a series of mergers.
Observations of the galaxy populations of three of the most massive, high
redshift (z=0.8-1.0) clusters known are presented. The evolution of
the galaxy properties are discussed in terms of their K band luminosity
functions, the K band Hubble diagram of brightest cluster galaxies and
their colour-magnitude relations. The luminosity functions probe the
epoch of assembly of the galaxies whilst the colour-magnitude relations
probe the epoch of star-formation. In both cases the bulk of the galaxies
are found to be consistent with passive evolution with a redshift of
formation of z_f > 2.
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