The XMM-LSS cluster sample and its cosmological applications
  We present the X-ray source detection procedure that we have developed for the purpose of assembling and characterizing controlled samples of cluster of galaxies for the XMM Large Scale Structure Survey. We describe how we model the selection function by means of simulations: this leads us to define source classes rather than flux limited samples. Focussing on the CFHTLS D1 area, our compilation suggests a cluster density higher than previously determined from the deep ROSAT surveys above a flux of 2.10^(-14) erg cm-2 s-1. We also present the L-T relation for the 9 brightest objects in the area. The slope is in good agreement with the local correlation. The relation shows luminosity enhancement for some of the 0.15<z<0.35 objects having 1<T<2 keV, a population that the XMM-LSS is for the first time systematically unveiling. 
M. Pierre (1), F. Pacaud (1) and the XMM-LSS consortium ((1)   DAPNIA/SAp CEA Saclay, Gif-sur-Yvette, France)