An Hst Lensing Survey of X-ray Luminous Galaxy Clusters: I. a 3831 Graham P. Smith, Jean-paul Kneib, Harald Ebeling, Oliver Czoske

We present an analysis of the mass distribution in the core of A 383 (z = 0.188), one of twelve X-ray luminous galaxy clusters at z ∼ 0.2 selected for a comprehensive and unbiased study of the mass distribution in massive galaxy clusters. Deep optical imaging performed by the Hubble Space Telescope (HST ) reveals a wide variety of gravitationally lensed features in the core of A 383, including a giant arc formed from the strongly-lensed images of two background galaxies, two radial arcs in the halo of the central cluster galaxy, several multiply-imaged arcs and numerous arclets. Based upon the constraints from the various lensed features, as well as from color information from ground-based observations, we construct a detailed model of the mass distribution in the central regions of the cluster, taking into account both the cluster-scale potential and perturbations from individual cluster galaxies. Keck spectroscopy of one component of the giant arc identifies it as an image of a star-forming galaxy at z = 1.01 and provides an accurate measurement of the mass of the cluster within the projected radius of the giant arc (65 kpc) of (3.5±0.1)×1013 M⊙. Using the weak shear measured from our HST observations we extend our mass model to larger scales and determine a mass of (1.8±0.2)×1014 M⊙ within a radius of 250 kpc. On smaller scales we employ the radial arcs as probes of the shape of the mass distribution in the cluster core (r < ∼ 20kpc), find that the mass profile is more peaked than a single Navarro, Frenk & White (NFW, 1997) profile. Our findings therefore support the proposal that massive cluster cores contain more mass than can be explained by a single cluster-scale NFW profile. The optical and X-ray properties of A 383 indicate the presence of a central cooling flow, for which we derive a mass deposition rate of > ∼ 200 M⊙ yr−1. We also use the X-ray emission from A 383 to obtain independent estimates of the total mass within projected radii of 65 and 250 kpc: (4.0+1.1 −1.7)×10 13 M⊙ and (1.2±0.5)×1014 M⊙, which are consistent with the lensing measurements. Subject headings: cosmology: observations — gravitational lensing — clusters of galaxies: individual: A 383 — galaxies: evolution