X-ray characterisation of the massive galaxy clusterClG-J104803.7+313843 at z=0.76 with XMM-Newton

TL;DR

This study uses XMM-Newton X-ray observations to characterize a rare, massive galaxy cluster at high redshift, determining its redshift, morphology, and mass, thereby enhancing understanding of cluster formation and evolution.

Contribution

The paper provides the first detailed X-ray based characterization of ClG-J104803.7+313843 at z=0.76, including its mass, morphology, and redshift, significantly improving previous measurements.

Findings

Cluster shows signs of merging activity in outskirts.

Mass of the cluster is approximately 5.64 x 10^14 solar masses.

X-ray data improved mass measurement by a factor of 3.5.

Abstract

We present the characterisation of the massive cluster ClG-J$104803.7+313843$ at $z=0.76$ performed using a serendipitous XMM-Newton observation. High redshift and massive objects represent an ideal laboratory to benchmark our understanding of how cluster form and assembly formation driven mainly by gravity.Leveraging the high throughput of XMM-Newton we were firstly able to determine the redshift of the object, shedding light on ambiguous photometric redshift associations. We investigated the morphology of this cluster which shows signs of merging activities in the outskirts and a flat core. We also measured the radial density profile up to $R_{500}$. With these quantities in hand, we were able to determine the mass, $M_{500}=5.64^{+0.79}_{-0.62} \times 10^{14}M_{\odot}$, using the YX proxy. This quantity improves previous measurement of the mass of this object by a factor of $\sim 3.5$. The characterisation of one cluster at such mass and redshift regime is fundamental as these objects are intrinsically rare, the number of objects discovered so far being less than $\sim 25$. Our study highlights the importance of using X-ray observations in combination with ancillary multi-wavelength data to improve our understanding of high-z and massive clusters