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: Brodwin, M., Ruel, J., Ade, Peter A. R., Aird, K. A., Andersson, K., Ashby, M. L. N., Bautz, M., Bazin, G., Benson, B. A., Bleem, L. E., Carlstrom, J. E., Chang, C. L., Crawford, T. M., Crites, A. T., de Haan, T., Desai, S., Dobbs, M. A., Dudley, J. P., Fazio, G. G., Foley, R. J., Forman, W. R., Garmire, G., George, E. M., Gladders, M. D., Gonzalez, A. H., Halverson, N. W., High, F. W., Holder, G. P., Holzapfel, W. L., Hrubes, J. D., Jones, C., Joy, M., Keisler, R., Knox, L., Lee, A. T., Leitch, E. M., Lueker, M., Marrone, D. P., McMahon, J. J., Mehl, J., Meyer, S. S., Mohr, J. J., Montroy, T. E., Murray, S. S., Padin, S., Plagge, T., Pryke, C., Reichardt, C. L., Rest, A., Ruhl, J. E.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOPScience 2010
• Subjects: QB Astronomy; South Pole; South pole
• Online Access: https://orca.cardiff.ac.uk/id/eprint/33741/; https://doi.org/10.1088/0004-637X/721/1/90

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 M (200) = 1.0(+0.6) (–0.4) × 10(15) M ☉, in agreement with the X-ray and SZE mass measurements. Combining masses from several independent measures leads to a best-estimate mass of M (200) = (7.95 ± 0.92) × 10(14 )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.