Cluster Cosmology Constraints from the 2500 deg^{2} SPTSZ Survey: Inclusion of Weak Gravitational Lensing Data from Magellan and the Hubble Space Telescope
Abstract
We derive cosmological constraints using a galaxy cluster sample selected from the 2500 deg^{2} SPTSZ survey. The sample spans the redshift range 0.25 < z < 1.75 and contains 343 clusters with SZ detection significance ξ > 5. The sample is supplemented with optical weak gravitational lensing measurements of 32 clusters with 0.29 < z < 1.13 (from Magellan and Hubble Space Telescope) and Xray measurements of 89 clusters with 0.25 < z < 1.75 (from Chandra). We rely on minimal modeling assumptions: (i) weak lensing provides an accurate means of measuring halo masses, (ii) the mean SZ and Xray observables are related to the true halo mass through powerlaw relations in mass and dimensionless Hubble parameter E(z) with a priori unknown parameters, and (iii) there is (correlated, lognormal) intrinsic scatter and measurement noise relating these observables to their mean relations. We simultaneously fit for these astrophysical modeling parameters and for cosmology. Assuming a flat νΛCDM model, in which the sum of neutrino masses is a free parameter, we measure Ω_{m} = 0.276 ± 0.047, σ _{8} = 0.781 ± 0.037, and σ _{8}(Ω_{m}/0.3)^{0.2} = 0.766 ±0.025. The redshift evolutions of the Xray Y _{X}mass and M _{gas}mass relations are both consistent with selfsimilar evolution to within 1σ. The mass slope of the Y _{X}mass relation shows a 2.3σ deviation from selfsimilarity. Similarly, the mass slope of the M _{gas}mass relation is steeper than selfsimilarity at the 2.5σ level. In a νwCDM cosmology, we measure the dark energy equationofstate parameter w = 1.55 ± 0.41 from the cluster data. We perform a measurement of the growth of structure since redshift z ̃ 1.7 and find no evidence for tension with the prediction from general relativity. This is the first analysis of the SPT cluster sample that uses direct weaklensing mass calibration and is a step toward using the much larger weaklensing data set from DES. We provide updated redshift and mass estimates for the SPT sample.
 Publication:

The Astrophysical Journal
 Pub Date:
 June 2019
 DOI:
 10.3847/15384357/ab1f10
 arXiv:
 arXiv:1812.01679
 Bibcode:
 2019ApJ...878...55B
 Keywords:

 cosmological parameters;
 cosmology: observations;
 galaxies: clusters: general;
 largescale structure of universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 Accepted for publication in ApJ (v2 is accepted version), the catalog can be found at https://pole.uchicago.edu/public/data/sptszclusters/