This page provides data products associated with the cosmological constraints using 178 square degrees of the South Pole Telescope (SPT) cluster survey as described in astro-ph/1112.5435, Benson et al 2011.

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 > 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-Newton.

Individual figures are available in PDF format here or bundled in a ZIP file here. Below we show a couple of example figures.

Assuming a LCDM cosmology, the two-dimensional marginalized constraints on sigma-8 and Omega-matter. Contours show the 68% and 95% confidence regions for the SPT+H0+BBN (red), CMB (gray), and CMB+SPT (blue) data sets. The black lines are the best-fit constraint (solid) and 68% confidence region (dashed) for the combination of parameters that the SPT+H0+BBN data set best constrains: sigma-8 (Omega-m/0.25)^{0.30} = 0.785 +/- 0.037.

Assuming a wCDM cosmology, the constraints on Omega-m, sigma-8, and w. The plots along the diagonal are the one-dimensional marginalized likelihood. The off-diagonal plots are the two-dimensional marginalized constraints showing the 68% and 95% confidence regions. We show the constraints for the CMB+BAO+SNe (gray, dashed), and CMB+BAO+SNe+SPT (green, solid) data sets. The SPT cluster data improves the constraints on sigma-8 and w, by factors of 1.4 and 1.25, respectively.

Assuming a LCDM cosmology with massive neutrinos and a free number of relativistic species, N-eff, the constraints on sigma-8, the sum of the neutrino masses, and N-eff. The plots along the diagonal are the one-dimensional marginalized likelihood. The off-diagonal plots are the two-dimensional marginalized constraints showing the 68% and 95% confidence regions. We show the constraints for the CMB+H0+BAO (gray, dashed), and CMB+H0+BAO+SPT (orange, solid) data sets. The black vertical line shows N-eff=3.046, the expected value for three neutrino species. Using the CMB+H0+BAO+SPT data set, the 68% confidence marginalized constraints are sigma-8=0.777 +/- 0.031, N-eff = 3.91 +/- 0.42, and the sum of the neutrino masses = 0.34 +/- 0.17 eV, with a 95% CL of < 0.63 eV.

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Contact:

jchyde.uchicago.edu

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egaltsevakicp.uchicago.edu

Last update:

September 7, 2011