HUBBLE-SPACE-TELESCOPE MEDIUM DEEP SURVEY .2. DECONVOLUTION OF WIDE-FIELD CAMERA FIELD GALAXY IMAGES IN THE 13(H)-DEGREES FIELD(43)

We present isophotal profiles of six faint field galaxies from some of the first deep images taken for the Hubble Space Telescope (HST) Medi um Deep Survey (MDS). These have redshifts in the range z = 0.126-0.40 1. The images were taken with the Wide Field Camera (WFC) in ''paralle l mode'' and deconvolved with the Lucy method using as the point-sprea d function nearby stars in the image stack-The WFC deconvolutions have a dynamic range of 16-20 dB (4-5 mag) and an effective resolution les s than or similar to 0.2'' (FWHM). The multiorbit HST images allow us to trace the morphology, light profiles, and color gradients of faint field galaxies down to V congruent-to 22-23 mag at sub-kpc resolution, since the redshift range covered is z = 0.1-0.4. The goals of the MDS are to study the sub-kpc scale morphology, light profiles, and color gradients for a larger sample of faint field galaxies down to V congru ent-to 23 mag, and to trace the fraction of early to late-type galaxie s as function of cosmic time. In this paper we study the brighter MDS galaxies in the 13h+43-degrees MDS field in detail, and investigate to what extent model fits with pure exponential disks or a1/4 bulges are justified at V less than or similar to 22 mag. Four of the six field galaxies have light profiles that indicate (small) inner bulges follow ing r1/4 laws down to 0.2'' resolution, plus a dominant surrounding ex ponential disk with little or no color gradients. Two occur in a group at z = 0.401, two are barred spiral galaxies at z = 0.179 and z = 0.3 02, and two are rather subluminous (and edge-on) disk galaxies at z = 0.126 and z = 0.179. Our deep MDS images can detect galaxies down to V , I less than or similar to 25-26 mag, and demonstrate the impressive potential of HST-even with its pre-refurbished optics-to resolve morph ological details in galaxies at cosmologically significant distances ( V less than or similar to 23 mag). Since the median redshift of these galaxies is less than or similar to 0.4, the HST resolution allows us to study sub-kpc size scales at the galaxy, which cannot be done with stable images over wide fields from the best ground-based sites.