A spectroscopic catalog of 10 distant rich clusters of galaxies

We present spectroscopic observations of galaxies in the fields of 10 dista nt clusters for which we have previously presented deep imaging with WFPC2 on board the Hubble Space Telescope. The clusters span the redshift range z = 0.37-0.56 and are the subject of a detailed ground- and space-based stud y to investigate the evolution of galaxies as a function of environment and epoch. The data presented here include positions, photometry, redshifts, s pectral line strengths, and classifications for 657 galaxies in the fields of the 10 clusters. The catalog is composed of 424 cluster members across t he 10 clusters and 233 held galaxies, with detailed morphological informati on from our WFPC2 images for 204 of the cluster galaxies and 71 in the fiel d. We illustrate some basic properties of the catalog, including correlatio ns between the morphological and spectral properties of our large sample of cluster galaxies. A direct comparison of the spectral properties of the hi gh-redshift cluster and field populations suggests that the phenomenon of s trong Balmer lines in otherwise passive galaxies (commonly called E + A but renamed here as the k + a class) shows an order-of-magnitude increase in t he rich cluster environment compared with a more modest increase in the fie ld population. This suggests that the process or processes involved in prod ucing k+a galaxies are either substantially more effective in the cluster e nvironment or that this environment prolongs the visibility of this phase. A more detailed analysis and modeling of these data is presented in Poggian ti et al.