The Redshift Dependence of Galaxy Clustering

Ray Carlberg
University of Toronto

Galaxy clustering is a fundamental statistic whose redshift dependence
tests the cosmological world model, the density fluctuation spectrum
and the statistical theory of galaxy formation. The Canadian Network
for Observational Cosmology field galaxy survey is designed to measure
the dynamics of clustering over the redshift range of 0 to about
0.7. We find a very slow decline of clustering with increasing
redshift, most consistent with biasing models in a low density flat
CDM universe. The red galaxies are a factor of about five more
clustered than the blue galaxies, whereas there is very little
dependence of clustering amplitude on luminosity. The density and
clustering of these galaxies is insufficient to cause the substantial
galaxy merging that builds up the mass of the galaxies, although the
low velocity dispersion groups are sites of on-going merging.  We
conclude that galaxy clustering largely follows the clustering of dark
matter halos and that the clustering amplitude is a major factor
current in controlling the current star formation rates of galaxies.