Cosmological Constraints from Sunyaev-Zel'dovich-Selected Clusters with X-ray Observations in the First 178 Square Degrees of the South Pole Telescope Survey
Creators: name: Benson, B. A.
name: de Haan, T.
name: Dudley, J. P.
name: Reichardt, C. L.
name: Aird, K. A.
name: Andersson, K.
name: Armstrong, R.
name: Bautz, M.
name: Bayliss, M.
name: Bazin, G.
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: Desai, S.
name: Dobbs, M. A.
name: Foley, R. J.
name: Forman, W. R.
name: George, E. M.
name: Gladders, M. D.
name: Halverson, N. W.
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: Rest, A.
name: Ruel, J.
name: Ruhl, J. E.
name: Saliwanchik, B. R.
name: Saro, A.
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: Suhada, R.
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: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We use measurements from the South Pole Telescope (SPT) Sunyaev Zel'dovich (SZ) cluster survey in combination with X-ray measurements to constrain cosmological parameters. We present a statistical method that fits for the scaling relations of the SZ and X-ray cluster observables with mass while jointly fitting for cosmology. The method is generalizable to multiple cluster observables, and self-consistently accounts for the effects of the cluster selection and uncertainties in cluster mass calibration on the derived cosmological constraints. We apply this method to a data set consisting of an SZ-selected catalog of 18 galaxy clusters at z &gt; 0.3 from the first 178 deg2 of the 2500 deg2 SPT-SZ survey, with 14 clusters having X-ray observations from either Chandra or XMM. Assuming a spatially flat LCDM cosmological model, we find the SPT cluster sample constrain sigma_8 (Omega_m/0.25)^0.30 = 0.785 +- 0.037. In combination with measurements of the CMB power spectrum from the SPT and the seven-year WMAP data, the SPT cluster sample constrain sigma_8 = 0.795 +- 0.016 and Omega_m = 0.255 +- 0.016, a factor of 1.5 improvement on each parameter over the CMB data alone. We consider several extensions beyond the LCDM model by including the following as free parameters: the dark energy equation of state (w), the sum of the neutrino masses (sum mnu), the effective number of relativistic species (Neff), and a primordial non-Gaussianity (fNL). We find that adding the SPT cluster data significantly improves the constraints on w and sum mnu beyond those found when using measurements of the CMB, supernovae, baryon acoustic oscillations, and the Hubble constant. Considering each extension independently, we best constrain w=-0.973 +- 0.063 and the sum of neutrino masses sum mnu &lt; 0.28 eV at 95% confidence, a factor of 1.25 and 1.4 improvement, respectively, over the constraints without clusters. [abbrev.]
description: 21 pages, 8 figures, submitted to ApJ