Searching for clusters using weak lensing
M. Hetterscheidt, T. Erben, Peter Schneider · 2004
Measuring the distribution and structures of galaxy clusters in a large redshift interval provides crucial information about the history and the large scale structure of the Universe.Weak gravitational lensing provides an opportunity to measure the (projected) mass distribution without any simplifying assumptions, such as hydrostatic equilibrium of the intra-cluster gas and virial equilibrium.Aside from the analysis of already known galaxy clusters, weak lensing techniques can be used to perform a blind search for hitherto unknown mass concentrations.As a consequence a purely mass-selected cluster sample can be obtained which is not biased towards the baryonic content.We briefly describe the method and results of a cluster search using 50 randomly selected I-band images which were observed under excellent seeing conditions with the FORS1 camera at the VLT.Several significant peaks are detected in the weak lensing maps, which coincide with overdensities of the light distribution.