An Analytic Model of the Physical Properties of Galaxy Clusters

TL;DR

This paper presents an analytic model for the intergalactic medium in galaxy clusters, enabling detailed analysis of X-ray and Sunyaev-Zeldovich observations across the entire cluster, validated with real data.

Contribution

The paper introduces a new analytic polytropic model for galaxy clusters that accurately fits observational data, including cluster cores with cooling plasma.

Findings

Model fits X-ray and SZ data well

Accurately describes cluster cores with cooling plasma

Validated with multiple Chandra observations

Abstract

We introduce an analytic model of the diffuse intergalactic medium in galaxy clusters based on a polytropic equation of state for the gas in hydrostatic equilibrium with the cluster gravitational potential. This model is directly applicable to the analysis of X-ray and Sunyaev-Zeldovich Effect observations from the cluster core to the virial radius, with 5 global parameters and 3 parameters describing the cluster core. We validate the model using Chandra X-ray observations of two polytropic clusters, MS 1137.5+6625 and CL J1226.9+3332, and two cool core clusters, Abell 1835 and Abell 2204. We show that the model accurately describes the spatially resolved spectroscopic and imaging data, including the cluster core region where significant cooling of the plasma is observed.