The XMM-Newton wide-field survey in the COSMOS field: Statistical properties of clusters of galaxies

We present the results of a search for galaxy clusters in the first 36 XMM-Newton pointings on the Cosmic Evolution Survey (COSMOS) field. We reach a depth for a total cluster flux in the 0.5-2 keV band of 3 x 10(-15) ergs cm(-2) s(-1), having one of the widest XMM-Newton contiguous raster surveys, covering an area of 2.1 deg(2). Cluster candidates are identified through a wavelet detection of extended X-ray emission. Verification of the cluster candidates is done based on a galaxy concentration analysis in redshift slices of thickness 0.1-0.2 in redshift, using the multiband photometric catalog of the COSMOS field and restricting the search to z < 1. 3 and i(AB) < 25. We identify 72 clusters and derive their properties based on the X-ray cluster scaling relations. A statistical description of the survey in terms of the cumulative log ( N > S)- log S distribution compares well with previous results, although yielding a somewhat higher number of clusters at similar fluxes. The X-ray luminosity function of COSMOS clusters matches well the results of nearby surveys, providing a comparably tight constraint on the faint-end slope of alpha = 1. 93 +/- 0. 04. For the probed luminosity range of (8 x 10(42)) -(2 x 10(44)) ergs s(-1), our survey is in agreement with and adds significantly to the existing data on the cluster luminosity function at high redshifts and implies no substantial evolution at these luminosities to z =1.3.