The 160 Square DegreeROSATSurvey: The Revised Catalog of 201 Clusters with Spectroscopic Redshifts

Abstract

We present the revised catalog of galaxy clusters detected as extended X-ray sources in the 160 Square Degree ROSAT Survey, including spectroscopic redshifts and X-ray luminosities for 200 of the 201 members. The median redshift is z median ¼ 0:25, and the median X-ray luminosity is L X;median ¼ 4:2 Â 10 43 h À2 50 ergs s À1 (0.5-2.0 keV). This is the largest high-redshift sample of X-ray-selected clusters published to date. There are 73 objects at z > 0:3 and 22 objects at z > 0:5 drawn from a statistically complete flux-limited survey with a median object flux of 1:4 Â 10 À13 ergs cm À2 s À1 . We describe the optical follow-up of these clusters with an emphasis on our spectroscopy, which has yielded 155 cluster redshifts, 110 of which are presented here for the first time. These measurements, combined with 45 from the literature and other sources, provide nearcomplete spectroscopic coverage for our survey. We discuss the final optical identifications for the extended X-ray sources in the survey region and compare our results to similar X-ray cluster searches.

An S-shaped arc in the galaxy cluster RX J0054.0-2823

“…For the cluster members, the distribution is well peaked at cz = 87 775 km s −1 , with a dispersion σ = 675 km s −1 . The average coincides with the mean of two of the main central galaxies (#128 and #131), in good agreement with the redshift z = 0.292 given by Mullis et al (2003) for the cluster. The internal error in the galaxy redshifts is ∆v = 209 ± 30 km s −1 , so the intrinsic line-of-sight (rest frame) radial velocity dispersion of the cluster is σ 1D = √ σ 2 − ∆v 2 /(1 + z) = 497 km s −1 , and the 3D dispersion σ 3D = √ 3 σ 1D = 860 km s −1 .…”

“…The galaxy cluster RX J0054.0-2823 was identified as part of the 160 square degree ROSAT serendipity survey (Vikhlinin et al 1998;Mullis et al 2003). Our imaging observations of RX J0054.0-2823 consist of a series of 24 V-band and 39 I-band images, with an exposure time of 300 s each, acquired during two photometric dark nights on September 26 and 27, 2000, using SUSI2 at the ESO NTT.…”

The MCXC: a meta-catalogue of x-ray detected clusters of galaxies

“…A second exception to the general selection criteria concerns double or multiple systems, for which we retain measurements for each of the components instead of measurements of the whole system. If possible, we compared our duplicates identifications with those in other work (e.g., Mullis et al 2003) and find perfect agreement. A total of 558 MCXC entries list the properties of a cluster that is a member of more than one input catalogue, and for which the information from only one input catalogue has been retained.…”

“…For 400SD clusters we take the information given in the column Notes in Table 4 of Burenin et al (2007, information on alternative names is not used). For 160SD clusters we take the information given in the column Notes in Table 4 of Mullis et al (2003, information on alternative names is not used).…”

Cosmology with Clusters of Galaxies

“…These projects, which are now completed, include: the RIXOS survey [38], the ROSAT Deep Cluster Survey (RDCS, [139,138]), the Serendipitous HighRedshift Archival ROSAT Cluster survey (SHARC, [32], the Wide Angle ROSAT Pointed X-ray Survey of clusters (WARPS, [125]), the 160 deg 2 large area survey [117], the ROSAT Optical X-ray Survey (ROXS, [49]). ROSAT-HRI pointed observations have also been used to search for distant clusters in the Brera Multi-scale Wavelet catalog (BMW, [113]).…”