A CFH12k lensing survey of X-ray luminous galaxy clusters - II. Weak lensing analysis and global correlations

S Bardeau, G Soucail, JP Kneib, O Czoske, H Ebeling, P Hudelot, I Smail, Graham Smith

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71 Citations (Scopus)

Abstract

Aims. We present a wide-field multi-color survey of a homogeneous sample of eleven clusters of galaxies for which we measure total masses and mass distributions from weak lensing. This sample, spanning a small range in both X-ray luminosity and redshift, is ideally suited to determining the normalisation of scaling relations between X-ray properties of clusters and their masses ( the M-TX and the M-LX relations) and also estimating the scatter in these relations at a fixed luminosity. Methods. The eleven clusters in our sample are all X-ray luminous and span a narrow redshift range at z = 0.21 +/- 0.04. The weak lensing analysis of the sample is based on ground-based wide-field imaging obtained with the CFH12k camera on CFHT. We use the methodology developed and applied previously on the massive cluster Abell 1689. A Bayesian method, implemented in the IM2SHAPE software, is used to fit the shape parameters of the faint background galaxies and to correct for PSF smearing. A multi-color selection of the background galaxies is applied to retrieve the weak lensing signal, resulting in a background density of sources of - 10 galaxies per square arc minute. With the present data, shear profiles are measured in all clusters out to at least 2 Mpc ( more than 15' from the center) with high confidence. The radial shear profiles are fitted with different parametric mass profiles and the virial mass M-200 is estimated for each cluster and then compared to other physical properties. Results. Scaling relations between mass and optical luminosity indicate an increase of the M/L ratio with luminosity ( M/L. proportional to L-0.8) and a LX-M-200 relation scaling as L-X proportional to M-200(0.83 +/- 0.11) while the normalization of the M-200 proportional to T-X(3/2) relation is close to the one expected from hydrodynamical simulations of cluster formation as well as previous X-ray analyses. We suggest that the dispersion in the M-200 - T-X and M-200 - L-X relations reflects the different merging and dynamical histories for clusters of similar X-ray luminosities and intrinsic variations in their measured masses. Improved statistics of clusters over a wider mass range are required for a better control of the intrinsic scatter in scaling relations.
Original languageEnglish
Pages (from-to)449-466
Number of pages18
JournalAstronomy and Astrophysics
Volume470
Issue number2
DOIs
Publication statusPublished - 1 Aug 2007

Keywords

  • gravitational lensing
  • dark matter
  • galaxies : clusters : general

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