High-Redshift Cool-Core Galaxy Clusters Detected via the Sunyaev--Zel'dovich Effect in the South Pole Telescope Survey
Creators: name: Semler, D. R.
name: Šuhada, R.
name: Aird, K. A.
name: Ashby, M. L. N.
name: Bautz, M.
name: Bayliss, M.
name: Bazin, G.
name: Bocquet, S.
name: Benson, B. A.
name: Bleem, L. E.
name: Brodwin, M.
name: Carlstrom, J. E.
name: Chang, C. L.
name: Cho, H. M.
name: Clocchiatti, A.
name: Crawford, T. M.
name: Crites, A. T.
name: de Haan, T.
name: Desai, S.
name: Dobbs, M. A.
name: Dudley, J. P.
name: Foley, R. J.
name: George, E. M.
name: Gladders, M. D.
name: Gonzalez, A. H.
name: Halverson, N. W.
name: Harrington, N. L.
name: High, F. W.
name: Holder, G. P.
name: Holzapfel, W. L.
name: Hoover, S.
name: Hrubes, J. D.
name: Jones, C.
name: Joy, M.
name: Keisler, R.
name: Knox, L.
name: Lee, A. T.
name: Leitch, E. M.
name: Liu, J.
name: Lueker, M.
name: Luong-Van, D.
name: Mantz, A.
name: Marrone, D. P.
name: McDonald, M.
name: McMahon, J. J.
name: Mehl, J.
name: Meyer, S. S.
name: Mocanu, L.
name: Mohr, J. J.
name: Montroy, T. E.
name: Murray, S. S.
name: Natoli, T.
name: Padin, S.
name: Plagge, T.
name: Pryke, C.
name: Reichardt, C. L.
name: Rest, A.
name: Ruel, J.
name: Ruhl, J. E.
name: Saliwanchik, B. R.
name: Saro, A.
name: Sayre, J. T.
name: Schaffer, K. K.
name: Shaw, L.
name: Shirokoff, E.
name: Song, J.
name: Spieler, H. G.
name: Stalder, B.
name: Staniszewski, Z.
name: Stark, A. A.
name: Story, K.
name: Stubbs, C. W.
name: van Engelen, A.
name: Vanderlinde, K.
name: Vieira, J. D.
name: Vikhlinin, A.
name: Williamson, R.
name: Zahn, O.
name: Zenteno, A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report the first investigation of cool-core properties of galaxy clusters selected via their Sunyaev--Zel'dovich (SZ) effect. We use 13 galaxy clusters uniformly selected from 178 deg^2 observed with the South Pole Telescope (SPT) and followed up by the Chandra X-ray Observatory. They form an approximately mass-limited sample (&gt; 3 x 10^14 M_sun h^-1_70) spanning redshifts 0.3 &lt; z &lt; 1.1. Using previously published X-ray-selected cluster samples, we compare two proxies of cool-core strength: surface brightness concentration (cSB) and cuspiness (α). We find that cSB is better constrained. We measure cSB for the SPT sample and find several new z &gt; 0.5 cool-core clusters, including two strong cool cores. This rules out the hypothesis that there are no z &gt; 0.5 clusters that qualify as strong cool cores at the 5.4σ level. The fraction of strong cool-core clusters in the SPT sample in this redshift regime is between 7% and 56% (95% confidence). Although the SPT selection function is significantly different from the X-ray samples, the high-z cSB distribution for the SPT sample is statistically consistent with that of X-ray-selected samples at both low and high redshifts. The cool-core strength is inversely correlated with the offset between the brightest cluster galaxy and the X-ray centroid, providing evidence that the dynamical state affects the cool-core strength of the cluster. Larger SZ-selected samples will be crucial in understanding the evolution of cluster cool cores over cosmic time.
description: 9 pages, 5 figures. Version as published in December 20th, 2012 issue of ApJ