RASS-MCMF: A full-sky X-ray selected galaxy cluster catalog

• Published in: arXiv.org
• Main Authors: Klein, Matthias, Hernández-Lang, Daniel, Mohr, Joseph J, Bocquet, Sebastian, Singh, Aditya
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 29.08.2023
• Subjects: Algorithms; Galactic clusters; Optical counterparts (astronomy); Parameters; Red shift; Sky surveys (astronomy); X-ray astronomy
• ISSN: 2331-8422

We present the RASS-MCMF catalog of 8,465 X-ray selected galaxy clusters over 25,000 deg\(^2\) of extragalactic sky. The accumulation of deep, multiband optical imaging data, the development of the Multi-Component Matched Filter cluster confirmation algorithm (MCMF), and the release of the DESI Legacy Survey DR10 catalog makes it possible -- for the first time, more than 30 years after the launch of the ROSAT X-ray satellite -- to identify the majority of the galaxy clusters detected in the second ROSAT All-Sky-Survey (RASS) source catalog (2RXS). The resulting 90\% pure RASS-MCMF catalog is the largest ICM-selected cluster sample to date. RASS-MCMF probes a large dynamic range in cluster mass spanning from galaxy groups to the most massive clusters. The cluster redshift distribution peaks at \(z\sim0.1\) and extends to redshifts \(z\sim1\). Out to \(z\sim0.4\), the RASS-MCMF sample contains more clusters per redshift interval (\(dN/dz\)) than any other ICM-selected sample. In addition to the main sample, we present two subsamples with 6,924 and 5,516 clusters, exhibiting 95\% and 99\% purity, respectively.. We forecast the utility of the sample for a cluster cosmological study, using realistic mock catalogs that incorporate most observational effects, including the X-ray exposure time and background variations, the existence likelihood selection and the impact of the optical cleaning with the algorithm MCMF. Using realistic priors on the observable-mass relation parameters from a DES-based weak lensing analysis, we estimate the constraining power of the RASS-MCMF\(\times\)DES sample to be of 0.026, 0.033 and 0.15 (\(1\sigma\)) on the parameters \(\Omega_\mathrm{m}\), \(\sigma_8\) and \(w\), respectively.