SPT-CL J0546-5345: A MASSIVE z>1 GALAXY CLUSTER SELECTED VIA THE SUNYAEV–ZEL'DOVICH EFFECT WITH THE SOUTH POLE TELESCOPE
/ Authors
M. Brodwin, J. Ruel, P. Ade, K. Aird, K. Andersson, M. Ashby, M. Bautz, G. Bazin, B. Benson, L. Bleem
and 61 more authors
J. Carlstrom, C. Chang, T. Crawford, A. Crites, T. Haan, S. Desai, M. Dobbs, J. Dudley, G. Fazio, R. Foley, W. Forman, G. Garmire, E. George, M. Gladders, Anthony H. Gonzalez, N. Halverson, F. W. High, G. Holder, W. Holzapfel, J. Hrubeš, C. Jones, M. Joy, R. Keisler, L. Knox, Adrian T. Lee, Adrian T. Lee, E. Leitch, M. Lueker, D. Marrone, J. McMahon, J. McMahon, J. Mehl, S. Meyer, J. J. Mohr, T. Montroy, S. Murray, S. Padin, T. Plagge, T. Plagge, C. Pryke, C. Reichardt, A. Rest, J. Ruhl, K. Schaffer, L. Shaw, L. Shaw, E. Shirokoff, J. Song, H. Spieler, B. Stalder, S. Stanford, Z. Staniszewski, A. Stark, C. W. Stubbs, K. Vanderlinde, J. Vieira, A. Vikhlinin, R. Williamson, Y. Yang, O. Zahn, A. Zenteno
/ Abstract
We report the spectroscopic confirmation of SPT-CL J0546-5345 at 〈z〉 = 1.067. To date this is the most distant cluster to be spectroscopically confirmed from the 2008 South Pole Telescope (SPT) catalog, and indeed the first z>1 cluster discovered by the Sunyaev–Zel'dovich Effect (SZE). We identify 21 secure spectroscopic members within 0.9 Mpc of the SPT cluster position, 18 of which are quiescent, early-type galaxies. From these quiescent galaxies we obtain a velocity dispersion of 1179+232−167 km s−1, ranking SPT-CL J0546-5345 as the most dynamically massive cluster yet discovered at z>1. Assuming that SPT-CL J0546-5345 is virialized, this implies a dynamical mass of M200 = 1.0+0.6−0.4 × 1015 M☉, in agreement with the X-ray and SZE mass measurements. Combining masses from several independent measures leads to a best-estimate mass of M200 = (7.95 ± 0.92) × 1014 M☉. The spectroscopic confirmation of SPT-CL J0546-5345, discovered in the wide-angle, mass-selected SPT cluster survey, marks the onset of the high-redshift SZE-selected galaxy cluster era.
Journal: The Astrophysical Journal