Galaxy Clusters Discovered via the Sunyaev-Zel'dovich Effect in the 2500-Square-Degree SPT-SZ Survey

• Published in: The Astrophysical Journal Supplement Series
• Main Authors: Bleem, L. E., Crites, A. T., Lueker, M., Padin, S., Shirokoff, E., Staniszewski, Z., Williamson, R.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Astronomical Society 2015
• Subjects: cosmology: observations; galaxies: clusters: individual; large-scale structure of universe; Kavli; South Pole; South pole
• Online Access: https://doi.org/10.1088/0067-0049/216/2/27

We present a catalog of galaxy clusters selected via their Sunyaev-Zel'dovich (SZ) effect signature from 2500 deg^2 of South Pole Telescope (SPT) data. This work represents the complete sample of clusters detected at high significance in the 2500 deg^2 SPT-SZ survey, which was completed in 2011. A total of 677 (409) cluster candidates are identified above a signal-to-noise threshold of ξ = 4.5 (5.0). Ground- and space-based optical and near-infrared (NIR) imaging confirms overdensities of similarly colored galaxies in the direction of 516 (or 76%) of the ξ > 4.5 candidates and 387 (or 95%) of the ξ > 5 candidates; the measured purity is consistent with expectations from simulations. Of these confirmed clusters, 415 were first identified in SPT data, including 251 new discoveries reported in this work. We estimate photometric redshifts for all candidates with identified optical and/or NIR counterparts; we additionally report redshifts derived from spectroscopic observations for 141 of these systems. The mass threshold of the catalog is roughly independent of redshift above z ~ 0.25 leading to a sample of massive clusters that extends to high redshift. The median mass of the sample is M_(500c(Ïcrit)) ~ 3.5 x 10^(14)M_☉ h_(70)^(-1), the median redshift is z_(med) = 0.55, and the highest-redshift systems are at z > 1.4. The combination of large redshift extent, clean selection, and high typical mass makes this cluster sample of particular interest for cosmological analyses and studies of cluster formation and evolution. © 2015 American Astronomical Society. Received 2014 September 2; accepted 2014 December 14; published 2015 January 27. The South Pole Telescope is supported by the National Science Foundation through grant PLR-1248097. Partial support is also provided by the NSF Physics Frontier Center grant PHY-1125897 to the Kavli Institute of Cosmological Physics at the University of Chicago, the Kavli Foundation, and the Gordon and Betty Moore Foundation grant GBMF 947. Galaxy cluster research at ...