Galaxy Cluster Pressure Profiles as Determined by Sunyaev Zel'dovich Effect Observations with MUSTANG and Bolocam II: Joint Analysis of Fourteen Clusters

TL;DR

This study derives high-resolution pressure profiles of 14 galaxy clusters using SZ effect observations from MUSTANG and Bolocam, revealing ensemble and individual cluster characteristics, discrepancies with X-ray data, and substructure presence.

Contribution

It provides joint analysis of SZ data for 14 clusters with generalized NFW models, highlighting differences from X-ray profiles and identifying substructure in several clusters.

Findings

Ensemble average pressure profile parameters are consistent with previous studies.

Individual clusters show discrepancies with X-ray derived profiles.

Substructure detected in 6 out of 14 clusters.

Abstract

We present pressure profiles of galaxy clusters determined from high resolution Sunyaev-Zel'dovich (SZ) effect observations of fourteen clusters, which span the redshift range $ 0.25 < z < 0.89$. The procedure simultaneously fits spherical cluster models to MUSTANG and Bolocam data. In this analysis, we adopt the generalized NFW parameterization of pressure profiles to produce our models. Our constraints on ensemble-average pressure profile parameters, in this study $\gamma$, $C_{500}$, and $P_0$, are consistent with those in previous studies, but for individual clusters we find discrepancies with the X-ray derived pressure profiles from the ACCEPT2 database. We investigate potential sources of these discrepancies, especially cluster geometry, electron temperature of the intracluster medium, and substructure. We find that the ensemble mean profile for all clusters in our sample is described by the parameters: $[\gamma,C_{500},P_0] = [0.3_{-0.1}^{+0.1}, 1.3_{-0.1}^{+0.1}, 8.6_{-2.4}^{+2.4}]$, for cool core clusters: $[\gamma,C_{500},P_0] = [0.6_{-0.1}^{+0.1}, 0.9_{-0.1}^{+0.1}, 3.6_{-1.5}^{+1.5}]$, and for disturbed clusters: $[\gamma,C_{500},P_0] = [0.0_{-0.0}^{+0.1}, 1.5_{-0.2}^{+0.1},13.8_{-1.6}^{+1.6}]$. Four of the fourteen clusters have clear substructure in our SZ observations, while an additional two clusters exhibit potential substructure.