Joint analysis of X-ray and Sunyaev Zel'dovich observations of galaxy clusters using an analytic model of the intra-cluster medium

TL;DR

This paper presents a joint analysis method combining X-ray and SZ data with an analytic intra-cluster medium model to measure gas mass fractions and the Hubble constant independently of cosmology.

Contribution

It introduces a novel joint analysis approach that simultaneously models X-ray and SZ observations to extract cluster properties without relying heavily on cosmological assumptions.

Findings

Validated the model on high-quality data from two galaxy clusters.

Successfully measured the gas mass fraction profiles.

Provided constraints on the evolution of cluster gas with redshift.

Abstract

We perform a joint analysis of X-ray and Sunyaev Zel'dovich (SZ) effect data using an analytic model that describes the gas properties of galaxy clusters. The joint analysis allows the measurement of the cluster gas mass fraction profile and Hubble constant independent of cosmological parameters. Weak cosmological priors are used to calculate the overdensity radius within which the gas mass fractions are reported. Such an analysis can provide direct constraints on the evolution of the cluster gas mass fraction with redshift. We validate the model and the joint analysis on high signal-to-noise data from the Chandra X-ray Observatory and the Sunyaev-Zel'dovich Array for two clusters, Abell 2631 and Abell 2204.