The build-up of the colour-magnitude relation as a function of environment
We discuss the environmental dependence of galaxy evolution based on deep panoramic imaging of two distant clusters, RXJ0152.7−1257 at z = 0.83 and CL0016+1609 at z = 0.55, taken with Suprime-Cam on the Subaru Telescope as part of the PISCES project. By combining with the SDSS data as a local counterpart for comparison, we construct a large sample of galaxies that spans wide ranges in environment, time, and stellar mass (or luminosity). This allows us to conduct systematic and statistical analyses of the photometric properties of galaxies based on the colour–density diagrams, colour–magnitude relations, and luminosity functions. We find that colours of galaxies, especially those of faint galaxies (MV> M ∗ V + 1), change from blue to red at a break density as we go to denser regions. This trend is observed at all redshifts in our sample. Based on local and global densities of galaxies, we classify three environments: field, groups, and clusters, and look into the environmental dependence of galaxies in detail. In particular, we quantify how the colour-magnitude relation is built-up as a function of environment. We show that the bright-end of the cluster colour-magnitude