THE HST MEDIUM DEEP SURVEY - LIGHT PROFILES AND REDSHIFTS FOR FIELD GALAXIES WITH Z-LESS-THAN-OR-SIMILAR-TO-0.6

High-resolution isophotal light profiles have been determined for 36 f ield galaxies in images taken for the Hubble Space Telescope Medium De ep Survey prior to HSTs refurbishment mission. The images were obtaine d with the Wide Field Camera in ''parallel mode'' and deconvolved usin g the Lucy-Richardson image-restoration algorithm with a large library of observed stars as PSFs. From ground-based spectroscopy, redshifts have been determined for 32 of the galaxies, yielding z =0.026-0.554. The restored images, light profiles, and spectra of individual galaxie s are discussed. By fitting the light profiles with models of exponent ial disks and/or r(1/4) bulges, values for scale lengths (r(s) and/or r(e)) and bulge-to-disk ratios have been derived. Our main results are : (1) The measured half-light radii, r(hl), are in agreement with thos e obtained independently via multiparameter fitting of the raw data, v alidating recent tests of galaxy evolution models based on these angul ar-size determinations. However, since some redshifted objects that ar e clearly extended in the deconvolved images have been described as st ellar using fits to the aberrated data, application of the latter tech nique may result in a significant fraction of compact galaxies being m isclassified as stars. Understanding this bias towards errant stellar classifications is of considerable importance when using automated fit ting algorithms to address the contribution of compact objects to fain t galaxy counts. (2) The distribution of galaxy color as a function of redshift can be interpreted in terms of simple models for spectral ev olution and B/D ratios from the light-profile analysis. However, a few galaxies (<10%) are much redder than the upper envelope of convention al models and are likely to have high internal absorption due to dust lanes and/or dust associated with galaxy mergers. (3) Three galaxies i n this sample are close mergers with separations between 0.'' 7 and 1. '' 0. The occurrence of such systems is much larger than found in prev ious studies of HST Cycle 1-2 images. (C) 1997 American Astronomical S ociety.