The fossil starburst in M82

We present high-resolution optical and near-infrared HST observations of two adjacent regions in the fossil starburst region in M82, M82 B1 and B2. The presence of both the active and the fossil starburst in M82 provides a unique physical environment to study the stellar and dynamical evolution of star cluster systems. The cluster population in B2 is more heavily affected by internal extinction than that in B1, amounting to an excess extinction in B2 of A(V),(excess) similar or equal to 1.1 +/-0.3 mag. Preliminary age estimates date the cluster population in the fossil starburst between similar to2 x 10(8) and similar to 10(9) years. The radial luminosity profiles of the brightest clusters are more closely approximated by power laws than by a Gaussian model, in particular in their wings, which favours a slow star formation scenario.