We study the rest–frame ( U - V ) color–magnitude relation in 4 clusters at redshifts 0.7 – 0.8 , drawn from the ESO Distant Cluster Survey .
We confirm that red–sequence galaxies in these clusters can be described as an old , passively–evolving population and we demonstrate , by comparison with the Coma cluster , that there has been significant evolution in the stellar mass distribution of red–sequence galaxies since z \sim 0.75 .
The EDisCS clusters exhibit a deficiency of low luminosity passive red galaxies .
Defining as ‘ faint ’ all galaxies in the passive evolution corrected range 0.4 \gtrsim L / L _ { * } \gtrsim 0.1 , the luminous–to–faint ratio of red–sequence galaxies varies from 0.34 \pm 0.06 for the Coma cluster to 0.81 \pm 0.18 for the high redshift clusters .
These results exclude a synchronous formation of all red–sequence galaxies and suggest that a large fraction of the faint red galaxies in current clusters moved on to the red sequence relatively recently .
Their star formation activity presumably came to an end at z \lesssim 0.8 .