EDP Sciences
Free Access
Volume 481, Number 1, April I 2008
Page(s) 65 - 77
Section Cosmology (including clusters of galaxies)
DOI https://doi.org/10.1051/0004-6361:20078877
Published online 07 February 2008

A&A 481, 65-77 (2008)
DOI: 10.1051/0004-6361:20078877

The mass distribution of RX J1347-1145 from strong lensing

A. Halkola1, H. Hildebrandt1, T. Schrabback1, M. Lombardi2, M. Bradac3, 4, T. Erben1, P. Schneider1, and D. Wuttke1

1  Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn, Germany
    e-mail: halkola@astro.uni-bonn.de
2  European Southern Observatory, Karl-Schwarzschild-Strasse 2 85748 Garching bei München, Germany
3  Kavli Institute for Particle Astrophysics and Cosmology,2575 Sand Hill Rd. MS29, Menlo Park, CA 94025, USA
4  Department of Physics, University of California, Santa Barbara, CA 93106, USA

(Received 18 October 2007 / Accepted 7 January 2008)

Aims.We determine the central mass distribution of galaxy cluster RX J1347-1145 using strong gravitational lensing.
Methods.High-resolution HST/ACS images of the galaxy cluster RX J1347-1145 have enabled us to identify several new multiple-image candidates in the cluster, including a 5-image system with a central image. The multiple-images allow us to construct an accurate 2-dimensional mass map of the central part of the cluster. The modelling of the cluster mass includes the most prominent cluster galaxies modelled as truncated isothermal spheres and a smooth halo component that is described with 2 parametric profiles. The mass reconstruction is done using a Markov chain Monte Carlo method that provides us with a total projected mass density, as well as with estimates for the parameters of interest and their respective errors.
Results.Inside the Einstein radius of the cluster (~35'', or ~200 kpc, for a source at redshift 1.8), we obtain a total mass of (2.6 $\pm$ 0.1) $\times$ 10 $^{14}~M_{\odot}$. The mass profile of the cluster is well-fitted by both a Navarro, Frenk, and White profile with a moderate concentration of c = 5.3 +0.4-0.6 and r200 = 3.3 +0.2-0.1 Mpc, and a non-singular isothermal sphere with velocity dispersion $\sigma$ = 1949 $\pm$ 40 km s-1 and a core radius of $r_{\rm c}$ = 20 $\pm$ 2''. The mass profile agrees with previous mass estimates based on the X-ray emission from the hot intra-cluster gas, although the X-ray mass estimates are systematically lower than what we obtain with gravitational lensing.

Key words: gravitational lensing -- galaxies: clusters: individual: RX J1347-1145 -- galaxies: clusters: general -- cosmology: dark matter

© ESO 2008