%0 Generic
%A Zatloukal, Michael
%D 2008
%F heidok:8800
%K Galaxy cluster , survey , galaxy evolution , red sequence , photometric redshift
%R 10.11588/heidok.00008800
%T A Search for Distant Clusters of Galaxies in the COSMOS Field
%U https://archiv.ub.uni-heidelberg.de/volltextserver/8800/
%X The evolution of galaxy clusters and their members above z >= 1 is largely unclear at present due to the small number of known distant clusters. To probe this important period and witness the development of key cluster characteristics observed today, the HIROCS survey is establishing a statistically signicant 0.5 <= z <= 1.5 cluster sample. For this thesis, the HIROCS cluster selection function was studied in detail using a mock sky based on semi-analytical galaxy evolution simulations. Public and proprietary data were combined for the COSMOS field. A cluster search was performed, yielding a 0.5 <= z <= 1.59 catalog of clusters, including the first larger, uniformly selected sample of distant (z > 1.2) clusters published. Comparing the color evolution of X-ray bright and -dark clusters, the latter were found to contain fewer passive galaxies than their X-ray counterparts. Spectroscopic follow-up observations of four z ~ 0.85 candidates, three of them X-ray dark, were conducted to probe cluster detection biases related to this.  Using the distant cluster sample, it was shown that z >= 1.2 clusters predominantly contain blue galaxies with active star formation and a signicant fraction of interacting members, but that their early type galaxies are old and formed the bulk of their stars at zf >= 3, possibly zf >= 5, in excellent agreement with predictions from simulations.