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Description
There is a known tension between cosmological parameter constraints obtained from the primary cosmic microwave background (CMB) and those from galaxy cluster samples. One possible explanation for this discrepancy could be that the incompleteness of detected clusters is higher than estimated, and certain types of groups or clusters of galaxy have been missed in the past. 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 ROSAT All-Sky Survey (RASS), using a dedicated source detection and characterization algorithm optimized for extended sources. Our state-of-the-art algorithm includes multi-resolution filtering, source detection and characterization. Through extensive simulations, the detection efficiency and sample purity are investigated. Previous cluster catalogs in X-ray and other wave-bands, as well as spectroscopic and photometric redshifts of galaxies are used for the cluster identification. We report a catalog of galaxy clusters at high galactic latitude based on the ROSAT All-sky Survey, named as RASS-based extended X-ray Galaxy Cluster Catalog (RXGCC), which includes 944 groups and clusters. Out of this number, 641 clusters have been identified through intra-cluster medium (ICM) emission previously (Bronze), 154 known optical and infrared clusters are detected as X-ray clusters for the first time (Silver), and 149 identified as clusters for the first time (Gold). Based on 200 simulations, the contamination ratio of the detections which were identified as clusters by ICM emission, and the detections which were identified as optical and infrared clusters in previous work is 0.008 and 0.100, respectively. Compared with Bronze sample, the Gold+Silver sample is less luminous, less massive, and has a flatter surface brightness profile. Specifically, the median flux in [0.1-2.4]keV band for Gold + Silver and Bronze sample is 2.496x10^-12^erg/s/cm^2^ and 4.955x10^-12^erg/s/cm^2^, respectively. The median value of {beta} (the slope of cluster surface brightness profile) is 0.76 and 0.83 for Gold + Silver and Bronze sample, respectively. This whole sample is available at https://github.com/wwxu/rxgcc.github.io/blob/master/table_rxgcc.fits.
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