Brightest X-ray clusters of galaxies in the CFHTLS wide fields: Catalog
  and optical mass estimator
  The CFHTLS presents a unique data set for weak lensing studies, having high
quality imaging and deep multi-band photometry. We have initiated an XMM-CFHTLS
project to provide X-ray observations of the brightest X-ray selected clusters
within the wide CFHTLS area. Performance of these observations and the high
quality of CFHTLS data, allows us to revisit the identification of X-ray
sources, introducing automated reproducible algorithms, based on the
multi-color red sequence finder. We have also introduced a new optical mass
proxy. We provide the calibration of the red sequence observed in the CFHT
filters and compare the results with the traditional single color red sequence
and photoz. We test the identification algorithm on the subset of highly
significant XMM clusters and identify 100% of the sample. We find that the
integrated z-band luminosity of the red sequence galaxies correlates well with
the X-ray luminosity with a surprisingly small scatter of 0.20 dex. We further
use the multi-color red sequence to reduce spurious detections in the full XMM
and RASS data sets, resulting in catalogs of 196 and 32 clusters, respectively.
We made spectroscopic follow-up observations of some of these systems with
HECTOSPEC and in combination with BOSS DR9 data. We also describe the
modifications needed to the source detection algorithm in order to keep high
purity of extended sources in the shallow X-ray data. We also present the
scaling relation between X-ray luminosity and velocity dispersion.
