Publication Date:
2015-05-23
Description:
Finding a sample of the most massive clusters with redshifts z 〉 0.6 can provide an interesting consistency check of the cold dark matter (CDM) model. Here, we present results from our search for clusters with 0.6 z 1.0 where the initial candidates were selected by cross-correlating the ROSAT All Sky Survey (RASS) faint and bright source catalogues with red galaxies from the Sloan Digital Sky Survey DR8. Our survey thus covers 10 000 deg 2 , much larger than previous studies of this kind. Deeper follow-up observations in three bands using the William Herschel Telescope and the Large Binocular Telescope were performed to confirm the candidates, resulting in a sample of 44 clusters for which we present richnesses and red sequence redshifts, as well as spectroscopic redshifts for a subset. At least two of the clusters in our sample are comparable in richness to RCS2- J 232727.7–020437, one of the richest systems discovered to date. We also obtained new observations with the Combined Array for Research in Millimeter Astronomy for a subsample of 21 clusters. For 11 of those we detect the Sunyaev–Zel'dovich effect signature. The Sunyaev–Zel'dovich signal allows us to estimate M 200 and check for tension with the cosmological standard model. We find no tension between our cluster masses and the CDM model.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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