Cluster Mass Profile from Lensing

Abstract

We propose a new technique to reconstruct non-parametrically the projected mass distribution of galaxy clusters from their gravitational lens effect on background galaxies. The beauty of our technique, is that it combines information from multiple imaging (strong lensing) and shear (weak lensing) as linear constraints on the projected mass distribution. Moreover, our technique overcomes all the drawbacks of non-linear methods. The method is applied to the first cluster-lens A370 and to the cluster-lens A2218 which is exceptionally rich in multiple images and arc(let)s. The reconstructed maps for both cases revealed unprecedented levels of detail.