The cluster galaxy luminosity function at z = 0 . 3 : a recent origin for the faint - end upturn ?

We derive deep luminosity functions (to Mz = −15) for galaxies in Abell 1835 (z = 0.25) and AC 114 (z = 0.31) and compare these with the local z luminosity function for 69 clusters. The data show that the faint-end upturn, the excess of galaxies above a single Schechter function at Mz < −17, does not exist in the higher redshift clusters. This suggests that the faint-end upturn galaxies have been created recently, by infall into clusters of star-forming field populations or via tidal disruption of brighter objects.