Witnessing a Galaxy Cluster Merger with JWST and a Chandra X-ray Temperature Map

TL;DR

This study combines JWST imaging with Chandra X-ray data to reveal detailed signs of a galaxy cluster merger, providing new insights into the cluster's dynamic state and intracluster medium.

Contribution

It presents the first high-fidelity X-ray temperature map of the merging galaxy cluster SMACSJ0723.3-7327, integrating JWST and Chandra data to uncover merger activity.

Findings

Clear signs of merger activity in the temperature map

ICM extends beyond JWST imagery boundaries

Reveals details of an actively merging cluster

Abstract

The first James Webb Space Telescope (JWST) image released was of galaxy cluster SMACSJ0723.3- 7327, a lensing cluster at z=0.39 showing detail only JWST can provide. While the majority of the focus has been on the brilliantly lensed galaxies at redshifts far beyond it, there is more to the story than it being just a lensing cluster. The Chandra X-ray temperature map tells a tale of a merging cluster with a significant subcluster leaving a wake in the intracluster medium (ICM). This paper presents a high fidelity temperature map of SMACSJ0723.3-7327 using adaptive circular binning, overlaid with the JWST image, showing clear signs of merger activity. As the ICM extends well past the boundaries of the JWST imagery, and no low-frequency radio observations are yet published, a fuller story of this cluster remains to be told. This new X-ray temperature map reveals new details of a moderately distant actively merging cluster.