Analysing Multi-Color Observations of Young Star Clusters in Mergers

We present a new evolutionary synthesis (ES) tool specifically developed for the analysis of multi-color data of young star clusters (YSCs) in interacting galaxies. Our ESO/ST-ECF ASTROVIRTEL1 project provides an unprecedented database of UV–optical–NIR observations from the HST/WFPC2, HST/NICMOS and VLT data archives. Comparison of these data with ES models for clusters of various metallicities which include gaseous emission as well as various degrees of dust extinction, allows one to independently determine metallicities, ages and extinction for individual clusters. These, in turn, are the basis to derive the mass functions of the YSC systems and to predict the future evolution of their luminosity functions and color distributions. Comparing YSC systems of various ages will, we anticipate, allow us to “see cluster disruption processes at work”.