Constraints on the Mass, Concentration, and Nonthermal Pressure Support of Six CLASH Clusters from a Joint Analysis of X-ray, SZ, and Lensing Data

TL;DR

This study combines X-ray, SZ, and lensing data to analyze six galaxy clusters, constraining their mass, concentration, and nonthermal pressure support, revealing tensions with simulation predictions.

Contribution

It provides the first joint multiwavelength analysis of CLASH clusters to constrain mass, concentration, and nonthermal pressure support with improved accuracy.

Findings

Joint analysis improves mass and concentration constraints.

Nonthermal pressure fraction at r500c is less than 0.11 at 95% confidence.

Results are in tension with hydrodynamical simulation predictions.

Abstract

We present a joint analysis of Chandra X-ray observations, Bolocam thermal Sunyaev-Zel'dovich (SZ) effect observations, Hubble Space Telescope (HST) strong lensing data, and HST and Subaru Suprime-Cam weak lensing data. The multiwavelength dataset is used to constrain parametric models for the distribution of dark and baryonic matter in a sample of six massive galaxy clusters selected from the Cluster Lensing And Supernova survey with Hubble (CLASH). For five of the six clusters, the multiwavelength dataset is well described by a relatively simple model that assumes spherical symmetry, hydrostatic equilibrium, and entirely thermal pressure support. The joint analysis yields considerably better constraints on the total mass and concentration of the cluster compared to analysis of any one dataset individually. The subsample of five galaxy clusters is used to place an upper limit on the fraction of pressure support in the intracluster medium (ICM) due to nonthermal processes, such as turbulence and bulk flow of the gas. We constrain the nonthermal pressure fraction at r500c to be less than 0.11 at 95 percent confidence. This is in tension with state-of-the-art hydrodynamical simulations, which predict a nonthermal pressure fraction of approximately 0.25 at r500c for clusters of similar mass and redshift. This tension may be explained by the sample selection and/or our assumption of spherical symmetry.