The XMM-SERVS X-ray eXtended Galaxy Cluster (XVXGC) catalog

TL;DR

This paper presents the creation of a new catalog of extended galaxy clusters detected via X-ray observations from XMM-SERVS, aiming to address discrepancies in cosmological parameters by identifying previously undetected or mischaracterized clusters.

Contribution

The paper introduces a novel detection algorithm optimized for extended sources and provides the first comprehensive catalog of extended galaxy clusters from XMM-SERVS data, including new and previously known clusters.

Findings

Catalog includes 141 extended galaxy cluster candidates.

New clusters are generally fainter and have flatter surface brightness profiles.

Median flux and surface brightness slope differ between known and newly identified clusters.

Abstract

To explain the well-known tension between cosmological parameter constraints obtained from the primary CMB and those drawn from galaxy cluster samples, we propose a possible explanation for the incompleteness of detected clusters are higher than estimated. We aim to search for galaxy groups and clusters with particularly extended surface brightness distributions by creating a new X-ray-selected catalog of extended galaxy clusters from the XMM-SERVS data, based on a dedicated source detection and characterization algorithm that is optimized for extended sources. Our state-of-the-art algorithm is composed of wavelet filtering, source detection, and characterization. We make a visual inspection of the optical image, and spatial distribution of galaxies within the same redshift layer to confirm the existence of clusters and estimate the cluster redshift with the spectroscopic and photometric redshifts of galaxies. The growth curve analysis is used to characterize the detections. We report a catalog of extended X-ray galaxy clusters detected from the XMM-SERVS data, named the XMM- SERVS X-ray eXtended Galaxy Cluster (XVXGC) catalog. It includes 141 cluster candidates. Specifically, there are 52 clusters previously identified as clusters with the intra-cluster medium (ICM) emission (class 3), 37 ones previously known as optical or infrared clusters but detected as X-ray clusters for the first time (class 2), and 52 identified as clusters for the first time (class 1). Compared with the class3 sample, the 'class1+2' sample is systematically fainter, and exhibits a flatter surface brightness profile. The median flux in [0.1-2.4]keV band for 'class1+2' and class3 sample is 2.336e-14 and 3.163e-14erg/s/cm2, respectively. The median slope of surface brightness profile are 0.502 and 0.577 for the 'class1+2' and class 3 samples, respectively.