How Much Can We Learn From A Merging Cold Front Cluster? : Insights From X-ray Temperature and Radio Maps of Abell 3667

TL;DR

This study combines high-resolution X-ray and radio observations with advanced simulations to analyze the cold front and shock features in galaxy cluster Abell 3667, revealing insights into plasma processes and cluster merger dynamics.

Contribution

It introduces new high-resolution temperature maps and a 2D shock-finding algorithm, and compares observational data with state-of-the-art MHD simulations to understand cold front stability.

Findings

Shock statistics from X-ray and radio data agree with simulations.

Cold front stability is due to suppressed thermal conduction.

High-fidelity temperature maps reveal detailed shock structures.

Abstract

The galaxy cluster Abell 3667 is an ideal laboratory to study the plasma processes in the intracluster medium (ICM). High resolution Chandra X-ray observations show a cold front in Abell 3667. At radio wavelengths, Abell 3667 reveals a double radio-relic feature in the outskirts of the cluster. These suggest multiple merger events in this cluster. In this paper, we analyze the substantial archival X-ray observations of Abell 3667 from ChandraX-ray Observatory and compare these with existing radio observations as well as state-of-the-art AMR (Adaptive Mesh Refinement) MHD cosmological simulations using Enzo. We have used two temperature map making techniques, Weighted Voronoi Tessellation and Adaptive Circular Binning, to produce the high resolution and largest field-of-view temperature maps of Abell 3667. These high fidelity temperature maps allow us to study the X-ray shocks in the cluster using a new 2-dimensional shock-finding algorithm. We have also estimated the Mach numbers from the shocks inferred from previous ATCA radio observations. The combined shock statistics from the X-ray and radio data are in agreement with the shock statistics in a simulated MHD cluster. We have also studied the profiles of the thermodynamic properties across the cold front using 447 ksec from the combined Chandra observations on Abell 3667. Our results show that the stability of the cold front in Abell 3667 can be attributed to the suppression of the thermal conduction across the cold front by a factor of 100 - 700 compared to the classical Spitzer value.