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K. L. Thompson, J. A. Willick (Stanford University)
We describe the first cluster candidate catalog and spectroscopic follow-up of StaCS, a search for intermediate redshift clusters of galaxies. The search description and scientific goals are described in a companion poster (Willick & Thompson).
Our first field analyzed consists of 12 overlapping CTIO prime focus fields taken by the Lawrence Berkeley Laboratory Supernova Cosmology Project (SCP), totaling 0.7 square deg. Our galaxy catalog was generated with the Faint Object Classification and Analysis System (Valdez, 1993), which in turn was analyzed with a matched filter algorithm. We have found 13 cluster candidates with estimated 0.3 \leq z \leq 0.9 and have begun spectroscopic followup using the Hobby-Eberly Telescope (HET). None of these candidates is associated with any known group or cluster or with an X-ray source. Our first confirmation is of a cluster with an expected redshift z = 0.4 ±0.05 and a measured z = 0.401. We demonstrate the efficiency of our search/confirmation procedure, outline future work to refine our candidate parameter estimates, and discuss co-moving volume and completeness limits.
Given the number of candidates found so far and the size of the SCP database of deep images (~35 square deg.), we expect to generate a substantial catalog of confirmed clusters with well defined completeness limits. It will in turn serve as a starting point for a variety of cluster studies in addition to the cosmological tests that are the initial focus of this work.
This work is supported in part by the Research Corporation.