Cosmological Constraints from Galaxy Clusters in the 2500 Square-degree SPT-SZ Survey
We present cosmological parameter constraints obtained from galaxy clusters identified by their Sunyaev–Zel'dovich effect signature in the 2500 square-degree South Pole Telescope Sunyaev Zel'dovich (SPT-SZ) survey. We consider the 377 cluster candidates identified at z > 0.25 with a det...
| Published in: | The Astrophysical Journal |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
American Astronomical Society
2016
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| Subjects: | |
| Online Access: | https://authors.library.caltech.edu/72247/ https://authors.library.caltech.edu/72247/1/Haan_2016_ApJ_832_95.pdf https://authors.library.caltech.edu/72247/2/1603.06522v1.pdf https://resolver.caltech.edu/CaltechAUTHORS:20161122-121544091 |
| Summary: | We present cosmological parameter constraints obtained from galaxy clusters identified by their Sunyaev–Zel'dovich effect signature in the 2500 square-degree South Pole Telescope Sunyaev Zel'dovich (SPT-SZ) survey. We consider the 377 cluster candidates identified at z > 0.25 with a detection significance greater than five, corresponding to the 95% purity threshold for the survey. We compute constraints on cosmological models using the measured cluster abundance as a function of mass and redshift. We include additional constraints from multi-wavelength observations, including Chandra X-ray data for 82 clusters and a weak lensing-based prior on the normalization of the mass-observable scaling relations. Assuming a spatially flat ΛCDM cosmology, we combine the cluster data with a prior on H 0 and find σ_8 = 0.784 ± 0.039 and Ω_m = 0.289 ± 0.042, with the parameter combination σ_8(Ω_m/0.27)^(0.3) = 0.797 ± 0.031. These results are in good agreement with constraints from the cosmic microwave background (CMB) from SPT, WMAP, and Planck, as well as with constraints from other cluster data sets. We also consider several extensions to ΛCDM, including models in which the equation of state of dark energy w, the species-summed neutrino mass, and/or the effective number of relativistic species (N_(eff)) are free parameters. When combined with constraints from the Planck CMB, H_0, baryon acoustic oscillation, and SNe, adding the SPT cluster data improves the w constraint by 14%, to w = -1.023 ± 0.042. |
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