The dark matter distribution in z  ~  0.5 clusters of galaxies

I. Determining scaling relations with weak lensing masses ^⋆

¹ Université de Toulouse, UPS-Observatoire Midi-Pyrénées, IRAP, Toulouse, France
e-mail: foex.gael@gmail.com
² CNRS, Institut de Recherche en Astrophysique et Planétologie (IRAP), 14 avenue Edouard Belin, 31400 Toulouse, France
³ CNRS, Institut de Recherche en Astrophysique et Planétologie (IRAP), 9 avenue Colonel Roche, 31028 Toulouse Cedex 4, France
⁴ Laboratoire AIM, IRFU/Service d’Astrophysique, CEA/DSM, CNRS and Université Paris Diderot, Bât. 709, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
⁵ Laboratoire d’Astrophysique de Marseille (LAM), Université d’Aix-Marseille & CNRS, UMR 7326, 38 rue Frédéric Joliot-Curie, 13388 Marseille Cedex 13, France
⁶ Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark

Received: 6 February 2012
Accepted: 19 August 2012

Abstract

The total mass of clusters of galaxies is a key parameter for studing massive halos. It relates to numerous gravitational and baryonic processes at play in the framework of large-scale structure formation, thus rendering its determination both important and challenging. From a sample of the 11 X-ray bright clusters selected from the EXCPRES sample, we investigate the optical and X-ray properties of clusters with respect to their total mass derived from weak gravitational lensing. From multicolor, wide-field imaging obtained with MegaCam at CFHT, we derive the shear profile of each individual cluster of galaxies. We carefully investigate all systematic sources related to the weak lensing mass determination. The weak lensing masses are then compared to the X-ray masses obtained from the analysis of XMM-Newton observations assuming hydrostatic equilibrium. We find good agreement between the two mass proxies although a few outliers with either perturbed morphology or poor quality data prevent deriving robust mass estimates. The weak lensing mass is also correlated with the optical richness and the total optical luminosity, as well as with the X-ray luminosity, to provide scaling relations within the redshift range 0.4 < z < 0.6. These relations are in good agreement with previous works at lower redshifts. For the L_X − M relation we combine our sample with two other cluster and group samples from the literature, thus covering two decades in mass and X-ray luminosity, with a regular and coherent correlation between the two physical quantities.