Mapping Stellar Evolution in the Wake of Density Waves in Ring Galaxies

Abstract

We have been conducting multi-color observations of a sample of classical ring galaxies with the aim of using them to study the formation and evolution of massive stars. We compare theoretical predictions for the expected color of the material inside the rings assuming that massive stars are created in the wake of the expanding wave. We present ground based data for VIIZw466 and HST data for IIZw28 and the Cartwheel which show strong color gradients.