SPT-CL J0546-5345: A MASSIVE z >1 GALAXY CLUSTER SELECTED VIA THE SUNYAEV-ZEL’DOVICH EFFECT WITH THE SOUTH POLE TELESCOPE

• Published in: The Astrophysical Journal
• Main Authors: Andersson, Karl, Bautz, Marshall W., Brodwin, M., Ruel, J., Ade, P. A. R., Aird, K. A., Ashby, M. L. N., Bazin, G., Benson, Bradford A., Bleem, L. E.
• Other Authors: MIT Kavli Institute for Astrophysics and Space Research
• Format: Article in Journal/Newspaper
• Language: English
• Published: IOP Publishing 2010
• Subjects: South Pole; South pole
• Online Access: http://hdl.handle.net/1721.1/96023

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[superscript +232 subscript −167] km s[superscript −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 M[subscript 200] = 1.0[superscript +0.6 subscript −0.4] × 10[superscript 15] M[subscript ☉], in agreement with the X-ray and SZE mass measurements. Combining masses from several independent measures leads to a best-estimate mass of M[subscript 200] = (7.95 ± 0.92) × 10[superscript 14] M[subscript ☉]. 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. United States. National Aeronautics and Space Administration (Jet Propulsion Laboratory (U.S.)) Smithsonian Astrophysical Observatory (Chandra X-ray Observatory (U.S.) Contract SV4-74018, A31) W. M. Keck Foundation