Application of a Self-Similar Pressure Profile to Sunyaev-Zel'dovich Effect Data from Galaxy Clusters

TL;DR

This paper introduces a self-similar pressure profile model for galaxy clusters that effectively fits Sunyaev-Zel'dovich effect data across large scales, aligning well with X-ray measurements and enabling detailed cluster property analysis.

Contribution

The study presents a new self-similar pressure profile derived from simulations, validated against SZ and X-ray data, improving cluster modeling over a broad radial range.

Findings

Parameters from joint SZ and X-ray fits agree with X-ray-only analysis.

The pressure profile yields electron temperature profiles consistent with spectroscopic X-ray data.

The model accurately describes cluster pressure profiles from core to virial radius.

Abstract

We investigate the utility of a new, self-similar pressure profile for fitting Sunyaev-Zel'dovich (SZ) effect observations of galaxy clusters. Current SZ imaging instruments - such as the Sunyaev-Zel'dovich Array (SZA) - are capable of probing clusters over a large range in physical scale. A model is therefore required that can accurately describe a cluster's pressure profile over a broad range of radii, from the core of the cluster out to a significant fraction of the virial radius. In the analysis presented here, we fit a radial pressure profile derived from simulations and detailed X-ray analysis of relaxed clusters to SZA observations of three clusters with exceptionally high quality X-ray data: A1835, A1914, and CL J1226.9+3332. From the joint analysis of the SZ and X-ray data, we derive physical properties such as gas mass, total mass, gas fraction and the intrinsic, integrated Compton y-parameter. We find that parameters derived from the joint fit to the SZ and X-ray data agree well with a detailed, independent X-ray-only analysis of the same clusters. In particular, we find that, when combined with X-ray imaging data, this new pressure profile yields an independent electron radial temperature profile that is in good agreement with spectroscopic X-ray measurements.