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Description
The discovery of new galaxy clusters is important for two reasons. First, clusters are interesting per se, since their detailed analysis allows us to understand how galaxies form and evolve in various environments and second, they play an important part in cosmology because their number as a function of redshift gives constraints on cosmological parameters. We have searched for galaxy clusters in the Stripe 82 region of the Sloan Digital Sky Survey, and analysed various properties of the cluster galaxies. Based on a recent photometric redshift (hereafter photo-z) galaxy catalogue, we built a cluster catalogue by applying the Adami & MAzure Cluster FInder (AMACFI). Extensive tests were made to fine-tune the AMACFI parameters and make the cluster detection as reliable as possible. The same method was applied to the Millennium simulation to estimate our detection efficiency and the approximate masses of the detected clusters. Considering all the cluster galaxies (i.e. within a 1Mpc radius of the cluster to which they belong and with a photo-z differing by less than +/-0.05 from that of the cluster), we stacked clusters in various redshift bins to derive colour-magnitude diagrams and galaxy luminosity functions (GLFs). For each galaxy brighter than Mr<-19.0, we computed the disk and spheroid components by applying SExtractor, and by stacking clusters we determined how the disk-to-spheroid flux ratio varies with cluster redshift and mass.
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