SPT-CL J0546-5345: A Massive z>1 Galaxy Cluster Selected Via the Sunyaev-Zel'dovich Effect with the South Pole Telescope
Abstract
We report the spectroscopic confirmation of SPT-CL J0546-5345 at langzrang = 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 × 1015 M sun, 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) × 1014 M sun. 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.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 2010
- DOI:
- 10.1088/0004-637X/721/1/90
- arXiv:
- arXiv:1006.5639
- Bibcode:
- 2010ApJ...721...90B
- Keywords:
-
- galaxies: clusters: individual: SPT-CL J0546-5345;
- galaxies: distances and redshifts;
- galaxies: evolution;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- ApJ, in press