Quasar Absorbing Galaxies atz≲ 1: Deep Imaging and Spectroscopy in the Field of 3C 336

We present very deep WFPC2 images and FOS spectroscopy from the Hubble SpaceTelescope (HST) together with numerous supporting ground-based observations ofthe field of the quasar 3C 336 ($z_{em}=0.927$). The observations are designedto investigate the nature of galaxies producing metal line absorption systemsin the spectrum of the QSO. Along a single line of sight, we find at least 6metal line absorption systems (of which 3 are newly discovered) ranging inredshift from 0.317 to 0.892. Through an extensive program of optical and IRimaging, QSO spectroscopy, and faint galaxy spectroscopy, we have identified 5of the 6 metal line absorption systems with luminous (L_K > 0.1 L*_K) galaxies.These have morphologies ranging from very late-type spiral to S0, and exhibit awide range of inclination and position angles with respect to the QSOsightline. The only unidentified absorber, despite our intensive search, is adamped Lyman $\alpha$ system at $z_{abs}=0.656$. Analysis of the absorptionspectrum suggests that the metal abundances ([Fe/H]$=-1.2$) in this system aresimilar to those in damped systems at $z \sim 2$, and to the two other dampedsystems for which abundances have been determined at $z <1$. We have found noexamples of intrinsically faint galaxies ($L < 0.1 L^{\ast}$) at small impactparameters that might have been missed as absorber candidates in our previousground-based imaging and spectroscopic programs on MgII absorbing galaxies.There are no bright galaxies (L > 0.1 L_K) within 50h^{-1} kpc which do notproduce detectable metal lines (of Mg II 2796, 2803 and/or C IV 1548, 1550) inthe QSO spectrum. All of these results generally support the inferences whichwe have previously reached from a larger survey for absorption-selectedgalaxies at $z\simlt 1$.Comment: 32 pages latex (AAS v4.0 style). 8 Postscript figures (including HST plate) available at ftp://astro.caltech.edu/users/ccs/3c336_figs.ps.gz . Submitted to Ap