2007ApJ...654..172D

Using the multiwavelength photometric and spectroscopic data covering the Chandra Deep Field South obtained within the Great Observatories Origins Deep Survey, we investigate the rest-frame UV properties of galaxies to z∼2.2, including the evolution of the luminosity function, the luminosity density, star formation rate (SFR), and galaxy morphology. We find a significant brightening (∼1 mag) in the rest-frame 2800 Å characteristic magnitude (M*) over the redshift range 0.3≲z≲1.7 and no evolution at higher redshifts. The rest-frame 2800 Å luminosity density shows an increase by a factor of ∼4 over the redshift range investigated. We estimate the SFR density to z∼2.2 from the 1500 and 2800 Å luminosities. When no correction for extinction is made, we find that the SFR derived from the 2800 Å luminosity density is almost a factor of 2 higher than that derived from the 1500 Å luminosities. Attributing this difference to differential dust extinction, we find that E(B-V)=0.20 results in the same extinction-corrected SFR from both 1500 and 2800 Å luminosities. The extinction-corrected SFR is a factor of ∼6.5 (∼3.7) higher than the uncorrected SFR derived from 1500 Å (2800 Å) luminosity. We investigate the morphological composition of our sample by fitting Sérsic profiles to the HST ACS galaxy images at a fixed rest-frame wavelength of 2800 Å at 0.5≲z≲2.2. We find that the fraction of apparently bulge-dominated galaxies (Sérsic index n>2.5) increases from ∼10% at z∼0.5 to ∼30% at z∼2.2. At the same time, we note that galaxies get bluer at increasing redshift. This suggests a scenario where an increased fraction of the star formation takes place in bulge-dominated systems at high redshift. This could be evidence that the present-day elliptical galaxies are a result of assembly (i.e., mergers) of galaxies at z≳1. Finally, we find that galaxy size for a luminosity-selected sample evolves as r_h∝(1+z)^–1.1 between redshifts z=2.2 and 1.1. This is consistent with previous measurements and suggests a similar evolution over the redshift range 0≲z≲6.