Southern Cosmology Survey II: Massive Optically-Selected Clusters from 70 square degrees of the SZE Common Survey Area

TL;DR

This paper catalogs 105 massive optically-selected galaxy clusters over 70 square degrees, providing their properties and cross-referencing X-ray data, aiming to support Sunyaev-Zeldovich Effect studies and cluster verification in mm-band surveys.

Contribution

It presents a new catalog of massive optically-selected galaxy clusters with detailed properties and cross-wavelength data, aiding SZE survey verification and cluster analysis.

Findings

Identification of 105 rich, massive clusters with optical and X-ray data.

Detection of gravitational lensing features in two clusters.

The catalog supports SZE survey validation and cluster studies.

Abstract

We present a catalog of 105 rich and massive ($M>3\times10^{14}M_{\sun}$) optically-selected clusters of galaxies extracted from 70 square-degrees 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-Zeldovich Effect (SZE) and therefore be detected in the wide-area mm-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 analyzes of the SZE data.