Detection of X-ray Clusters of Galaxies by Matching RASS Photons and SDSS Galaxies within GAVO

Abstract

A new method for a simultaneous search for clusters of galaxies in X-ray photon maps and optical galaxy maps is described. The merging of X-ray and optical data improves the source identification so that a large amount of telescope time for spectroscopic follow-up can be saved. The method appears thus ideally suited for the analysis of the recently proposed wide-angle X-ray missions like DUO and ROSITA. As a first application, clusters are extracted from the 3rd version of the ROSAT All-Sky Survey and the Early Date Release of the Sloan Digital Sky Survey (SDSS). The time-consuming computations are performed within the German Astrophysical Virtual Observatory (GAVO). On a test area of 140 square degrees, 75 X-ray clusters are detected down to an X-ray flux limit of $3-5\times 10^{-13}\mathrm{erg}{\mathrm{s}}^{-1}{\mathrm{cm}}^{-2}$ in the ROSAT energy band 0.1-2.4 keV. The clusters have redshifts $z\le 0.5$. The survey thus fills the gap between traditional large-area X-ray surveys and serendipitous X-ray cluster searches based on pointed observations, and has the potential to yield about 4,000 X-ray clusters after completion of SDSS.

19 pages, low-resolution figures, accepted for publication in Astronomy and Astrophysics

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Cited by in corpus (14)

• The ROSAT-ESO Flux Limited X-ray (REFLEX) Galaxy Cluster Survey. V. The cluster catalogue
• The galaxy cluster mass scale and its impact on cosmological constraints from the cluster population
• The 2XMMi/SDSS Galaxy Cluster Survey I. The first cluster sample and X-ray luminosity-temperature relation
• The 2XMMi/SDSS Galaxy Cluster Survey. II. The optically confirmed cluster sample and the L_X-T relation
• The scaling relation between richness and mass of galaxy clusters: a Bayesian approach
• ComPRASS: a Combined Planck-RASS catalogue of X-ray-SZ clusters
• Sunyaev-Zel'dovich observation of the Bullet-like cluster Abell 2146 with the Arcminute Microkelvin Imager
• The Serendipitous XMM-Newton Cluster Athens Survey (SEXCLAS): Sample selection and the cluster log N - log S
• The 3XMM/SDSS Stripe 82 Galaxy Cluster Survey: Cluster catalogue and discovery of two merging cluster candidates
• A matched filter approach for blind joint detection of galaxy clusters in X-ray and SZ surveys
• XMM-{\em Newton} Observations of Optically Selected SDSS Clusters
• The HectoMAP Cluster Survey - II. X-ray Clusters
• Joint signal extraction from galaxy clusters in X-ray and SZ surveys: A matched-filter approach
• VADER - A Satellite Mission Concept For High Precision Dark Energy Studies