New Constraints on the Luminosity Evolution of Spheroidal Galaxies in Distant Clusters

Abstract

We investigate various probes of luminosity evolution in the rich cluster environment, concentrating in particular on the spheroidal (E/S0) galaxies, using a newly constructed catalog of morphologically classified Hubble Space Telescope (HST) images of galaxies observed in the cores of 13 clusters with redshifts 0.17 < mu >e. At the standard condition corresponding to Re = 1 kpc, we find convincing evidence of evolutionary brightening in both rest frame B and K light, consistent with model predictions based on the passive evolution of stellar populations.