Southern Cosmology Survey. II. Massive Optically Selected Clusters from 70 Square Degrees of the Sunyaev-Zel'dovich Effect Common Survey Area

Abstract

We present a catalog of 105 rich and massive (M>3 × 10¹⁴ M _sun) optically selected clusters of galaxies extracted from 70 deg² of public archival griz imaging from the Blanco 4 m telescope acquired over 45 nights between 2005 and 2007. We use the clusters' optically derived properties to estimate photometric redshifts, optical luminosities, richness, and masses. We complement the optical measurements with archival XMM-Newton and ROSAT X-ray data which provide additional luminosity and mass constraints on a modest fraction of the cluster sample. Two of our clusters show clear evidence for central lensing arcs; one of these has a spectacular large diameter, nearly complete Einstein Ring surrounding the brightest cluster galaxy. A strong motivation for this study is to identify the massive clusters that are expected to display prominent signals from the Sunyaev-Zel'dovich effect (SZE) and therefore be detected in the wide-area millimeter-band surveys being conducted by both the Atacama Cosmology Telescope and the South Pole Telescope. The optical sample presented here will be useful for verifying new SZE cluster candidates from these surveys, for testing the cluster selection function, and for stacking analyses of the SZE data.