Redshift Measurements of Galaxy Clusters from the Swift Serendipitous Cluster Survey
Abstract
The Swift-XRT observations of gamma-ray bursts form an excellent serendipitous, medium-deep, soft X-ray survey, covering a sky area of 100 square degrees with a median flux limit of 4×10^-15 flux. The final survey will yield one of the largest uniformly selected X-ray cluster catalogs with ~1,200 clusters. Using SDSS, MDM 2.4m and KPNO 4m observations in the Northern hemisphere, we have confirmed 50% of the candidates as low redshift clusters (z < 0.5) and a fraction of the 0.5 < z < 0.8 clusters. Here, we propose to follow-up the Swift cluster candidates in the Southern hemisphere using the CTIO 4m telescope. In particular, we propose taking deep g/r/i/z images of ~140 Swift clusters using DECam to measure photometric redshifts up to z=1.0. This is important to constrain the completeness and purity of the catalog and to model the cluster selection function of the survey, so that the survey can be used to study structure evolution and cosmology. In addition, the sample will provide an important calibration data set for the DES cluster survey, allowing us to better calibrate and characterize the performance of the DES photometric cluster finders.
- Publication:
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NOAO Proposal
- Pub Date:
- February 2014
- Bibcode:
- 2014noao.prop..306D