Weak lensing density profiles and mass reconstructions of the galaxy clusters Abell 1351 and Abell 1995

Abstract

Aims: The aim of the present work is to study the overall mass distribution of the galaxy clusters Abell 1351 and Abell 1995 using weak gravitational lensing. These clusters have a very different mass structure and dynamical state and are the two extremes from a larger sample of 38 X-ray luminous clusters of similar size and redshift.
Methods: We measure the shear values of faint background galaxies and correct for PSF anisotropies using the KSB+ method. Two-dimensional mass maps of the clusters are created using a finite-field mass reconstruction algorithm, and verified with aperture mass statistics. The masses inferred from the reconstructions are compared to those obtained from fitting spherically symmetric SIS- and NFW-models to the tangential shear profiles. We discuss the NFW concentration parameters in detail.
Results: From the mass reconstructions we infer M_2D(<r₂₀₀)-masses of 11.7±3.1×10¹⁴ h₇₀^-1~M_⊙ and 10.5±2.7×10¹⁴ h₇₀^-1~M_⊙ for Abell 1351 and Abell 1995, respectively. About 3 arcmin northeast of the main mass peak of Abell 1351, we detect a significant secondary peak both in the mass reconstruction and from aperture mass statistics. This feature is also traced by cluster members selected by means of their V-I colour, and is therefore likely a real substructure of Abell 1351. From our fits to the tangential shear we infer masses of the order of M₂₀₀∼8-9×10¹⁴~h₇₀^-1~M_⊙ (Abell 1351) and M₂₀₀∼5-6×10¹⁴~h₇₀^-1~M_⊙ (Abell 1995). The concentration parameters remain poorly constrained by our weak lensing analysis.

Based on observations obtained with CFH12K at the

Canada-France-Hawaii Telescope (CFHT) which is operated by the

National Research Council of Canada, the Institut des Sciences de

l'Univers of the Centre National de la Recherche Scientifique and

the University of Hawaii.