The Canada-France Redshift Survey. VI. Evolution of the Galaxy Luminosity Function to Z approximately 1

Abstract

The cosmic evolution of the field galaxy population has been studied out to a redshift of z ∼ 1 using a sample of 730 I-band selected galaxies, of which 591 have secure redshifts with median ∼ 0.56. The trivariate luminosity function φ(M, color, z) shows unambiguously that the population evolves and that this evolution is strongly differential with color and, less strongly, with luminosity. The luminosity function of red galaxies shows very little change in either number density or luminosity over the entire redshift range 0 0.5. By 0.5 AB(B) ∼ -18, and these galaxies may possibly represent the descendants of the evolving blue population seen at higher redshifts. The changes seen in the luminosity function are also apparent in color-magnitude diagrams constructed at different epochs and in the V/Vmax statistic computed as a function of spectral type. Finally, it is argued that the picture of galaxy evolution presented here is consistent with the very much smaller samples of field galaxies that have been selected in other wave bands and with the results of studies of galaxies selected on the basis of Mg II λ2799 absorption.