Weak Lensing with the Very Large Telenscope
M. Lombardi & P. Rosati
European Southern Observatory, Karl-Schwarzschild-Str. 2,
D-85748, Garching, Germany

Abstract:
The cluster of galaxies MS1008${}.{}$1$-$1224, observed by the VLT Unit~1, provides a unique opportunity to make a detailed weak lensing mass reconstruction. The combination of deep exposure, good seeing, small instrument-induced distortions, and multi-band information allows us to obtain a reliable mass distribution and to study in detail the impact of systematic errors on weak lensing reconstructions. Moreover, the availability of radial velocities for $65$ galaxies in MS1008 from the CNOC survey (Carlberg et al. 1996), as well as X-ray spectroscopic observations, provide independent estimates of the total mass. The mass we obtain within $1 \, h_{50}^{-1}$ Mpc, $5.3 \times 10^{14} \, h^{-1}_{50} \mbox{ M}_\odot$ is in excellent agreement with X-ray estimates.}