HuanYuan Shan, Jean-Paul Kneib, Charling Tao, Zuhui Fan, Mathilde Jauzac, Marceau Limousin, Richard Massey, Jason Rhodes, Karun Thanjavur
We present the first weak gravitational lensing analysis of the completed
Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). We study the 64 square
degrees W1 field, the largest of the CFHTLS-Wide survey fields, and present the
largest contiguous weak lensing convergence "mass map" yet made. 2.66 million
galaxy shapes are measured, using a KSB pipeline verified against
high-resolution Hubble Space Telescope imaging that covers part of the CFHTLS.
Our i'-band measurements are also consistent with an analysis of independent
r'-band imaging. The reconstructed lensing convergence map contains 301 peaks
with signal-to-noise ratio {\nu}>3.5, consistent with predictions of a
{\Lambda}CDM model. Of these peaks, 126 lie within 3.0' of a BCG identified
from multicolor optical imaging in an independent, red sequence survey. We also
identify 7 counterparts for massive clusters previously seen in X-ray emission
within 6 square degrees XMM-LSS survey. With photometric redshift estimates for
the source galaxies, we use a tomographic lensing method to fit the redshift
and mass of each convergence peak. Matching these to the optical observations,
we confirm 85 groups/clusters with \chi^2 reduced < 3.0, at a mean redshift
= 0.36 and velocity dispersion <\sigma_c> = 658.8 km/s. Future surveys,
such as DES, LSST, KDUST and EUCLID, will be able to apply these same
techniques to map clusters in much larger volumes and thus tightly constrain
cosmological models.
View original:
http://arxiv.org/abs/1108.1981
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