The Nuclear Colors and Morphology of Field Galaxies at Moderate Redshift

Abstract

Until recently, the study of faint field galaxies has been limited by the spatial resolutions available to ground-based imaging. Here we present HST images with 0-1 resolution for a sample of 203 field galaxies with I <= 22 (corresponding to B <= 24.5). The expected median redshift for such a sample is z ~ 0.5. The high resolution of HST allows us to measure the nuclear (central-kiloparsec) color. We have also classified the morphological type of each galaxy and noted any signs of peculiarities or the presence of nearby galaxies. For the brightest third of the sample, familiar Hubble types have been assigned. Combining the types with nuclear colors, we find weak evidence that merging/interacting galaxies have bluer colors than noninteracting galaxies.