PROBING THE IGM/GALAXY CONNECTION. IV. THE LCO/WFCCD GALAXY SURVEY OF 20 FIELDS SURROUNDING UV-BRIGHT QUASARS

Abstract

We publish the survey for galaxies in 20 fields containing ultraviolet bright quasars (with z [subscript em] ≈ 0.1-0.5) that can be used to study the association between galaxies and absorption systems from the low-z intergalactic medium (IGM). The survey is magnitude limited (R ≈ 19.5 mag) and highly complete out to 10' from the quasar in each field. It was designed to detect dwarf galaxies (L ≈ 0.1L*) at an impact parameter ρ ≈ 1 Mpc (z = 0.1) from a quasar. The complete sample (all 20 fields) includes R-band photometry for 84,718 sources and confirmed redshifts for 2800 sources. This includes 1198 galaxies with 0.005 < z < (z [subscript em] – 0.01) at a median redshift of 0.18, which may associated with IGM absorption lines. All of the imaging was acquired with cameras on the Swope 40'' telescope and the spectra were obtained via slit mask observations using the WFCCD spectrograph on the Dupont 100'' telescope at Las Campanas Observatory. This paper describes the data reduction, imaging analysis, photometry, and spectral analysis of the survey. We tabulate the principal measurements for all sources in each field and provide the spectroscopic data set online.