The Luminosity, Stellar Mass, and Number Density Evolution of Field   Galaxies of Known Morphology from z = 0.5 - 3
  The evolution of rest-frame B-band luminosities, stellar masses, and number densities of field galaxies in the Hubble Deep Field North and South are studied as a function of rest-frame B-band morphological type out to redshifts z~3 using a sample of 1231 I < 27 galaxies with spectroscopic and photometric redshifts. We find that the co-moving number, and relative number, densities of ellipticals and spirals declines rapidly at z > 1, although examples exist at z > 2. The number and number fraction of peculiar galaxies consistent with undergoing major mergers rises consistently at redshifts z > 2. Through simulations we argue that this decline is robust at the 4 sigma level against morphological k-corrections and redshift effects. We trace the evolution of rest-frame B-band luminosity density as a function of morphology out to z~3 finding that the luminosity density is steadily dominated by peculiars at z > 1.5 with a peak fraction of 60-90% at z~3. By z~0.5 B-band luminosity fractions are similar to their local values. The stellar mass density follows a similar trend as the luminosity density, with some important exceptions. At high redshifts, z > 2, over 60-80% of stellar mass is attached to peculiars, while at z< 1, 80-95% of stellar mass is attached to ellipticals and spirals. In contrast to the luminosity density, the stellar mass density of ellipticals is greater than spirals at z < 1.5, and the stellar masses in both types grow together at z < 1, while number densities remain constant. (abridged) 
Christopher J. Conselice, Jeffrey A. Blackburne, Casey Papovich