Joint X-ray/Sunyaev-Zel'dovich Analysis of the Intra-Cluster Medium

TL;DR

This study combines X-ray and Sunyaev-Zel'dovich data to analyze intra-cluster gas properties, revealing temperature decline and entropy profiles without relying on traditional spectroscopic methods, thus reducing modeling biases.

Contribution

It introduces a non-parametric de-projection method that jointly uses X-ray and SZ imaging to measure intra-cluster gas properties independently of X-ray spectroscopy.

Findings

Gas temperature decreases in cluster outskirts.

Gas entropy profile measured independently of spectroscopy.

Systematic uncertainties from SZ are smaller than spectroscopic errors.

Abstract

We present results from a joint X-ray/Sunyaev-Zel'dovich modeling of the intra-cluster gas using XMM-Newton and APEX-SZ imaging data. The goal is to study the physical properties of the intra-cluster gas with a non-parametric de-projection method that is, aside from the assumption of spherical symmetry, free from modeling bias. We demonstrate a decrease of gas temperature in the cluster outskirts, and also measure the gas entropy profile, both of which are obtained for the first time independently of X-ray spectroscopy, using Sunyaev-Zel'dovich and X-ray imaging data. The contribution of the APEX-SZ systematic uncertainties in measuring the gas temperature at large radii is shown to be small compared to the XMM-Newton and Chandra systematic spectroscopic errors.