Baryon content in a sample of 91 galaxy clusters selected by the South Pole Telescope at 0.2 <z < 1.25

Abstract

We estimate total mass (M 500), intracluster medium (ICM) mass (M ICM), and stellar mass (M) in a Sunyaev-Zel'dovich effect (SZE) selected sample of 91 galaxy clusters with masses M 500 2.5 × 10 14 M and redshift 0.2 < z < 1.25 from the 2500 deg 2 South Pole Telescope SPT-SZ survey. The total masses M 500 are estimated from the SZE observable, the ICM masses M ICM are obtained from the analysis of Chandra X-ray observations, and the stellar masses M are derived by fitting spectral energy distribution templates to Dark Energy Survey griz optical photometry and WISE or Spitzer near-infrared photometry. We study trends in the stellar mass, the ICM mass, the total baryonic mass, and the cold baryonic fraction with cluster halo mass and redshift. We find significant departures from self-similarity in the mass scaling for all quantities, while the redshift trends are all statistically consistent with zero, indicating that the baryon content of clusters at fixed mass has changed remarkably little over the past ≈9 Gyr. We compare our results to the mean baryon fraction (and the stellar mass fraction) in the field, finding that these values lie above (below) those in cluster virial regions in all but the

Cosmology dependence of galaxy cluster scaling relations

“…Consistently with Chiu et al (2018), we find that the mass slope is smaller than one (i.e. α + αss ∼ 0.9).…”

“…In the right-hand panel of Fig A.1, we show the cosmology dependence of α, β and σ for M * -M vir scaling relation (empty triangles). The dark grey shaded region is represents observational uncertainties taken from Chiu et al (2018), centered at C8 cosmology (see their Table 3). Chiu et al (2018) use DES and WISE/Spitzer data to constrain M * -M 500c scaling relation for galaxy clusters in the redshift range 0.2 < z < 1.25, with masses M 500c 2.5 × 10 14 M .…”

The richness-to-mass relation of CAMIRA galaxy clusters from weak-lensing magnification in the Subaru Hyper Suprime-Cam survey

“…Finally, we randomly sample the value of M 500 for each cluster from their resulting P(M 500 |N, z). This approach has been widely used in previous work (e.g., Chiu et al 2018a), which demonstrates a statistically robust method for inferring individual cluster masses from ensemble population modeling .…”

“…Specifically, we assume an underlying N-M relation characterized by its log-normal intrinsic scatter at fixed mass and evaluate the probability of observing the weak-lensing magnification signal for a given richness. This method has been widely used in previous work to calibrate the observable-to-mass relation of a cluster sample with a well-defined selection function (Chiu et al 2016b;Chiu et al 2018a;Bulbul et al 2018). In addition, the effects of Malmquist and Eddington bias are fully accounted for in this approach.…”

XXL Survey groups and clusters in the Hyper Suprime-Cam Survey. Scaling relations between X-ray properties and weak lensing mass

“…There is some evidence that these results are stable with respect to mass and redshift range and selection methods (Chiu et al 2016(Chiu et al , 2018a. Chiu et al (2018a) analyzed 91 massive galaxy clusters (M500 1.5 × 10 14 M ) selected by the South Pole Telescope SPT-SZ survey. Exploiting masses estimated from the SZE (Sunyaev-Zel'dovich effect), they found a slope of ∼ 1.3 and no significant redshift evolution over a large redshift range (0.2 < z < 1.25).…”