Abstract details

Qualitatively, the built-up of molecular gas in a circum-nuclear ring is a well-understood phenomenon, explained in the context of dynamical resonances between the gas and a stellar bar. However, the question of how star formation is triggered and regulated in these rings is much less clear. In order to shed light on some aspects of this topic, we have used the integral-field spectrograph SINFONI on the VLT for a study of circum-nuclear star burst rings in six nearby spiral galaxies. After a brief review of the open questions, this talk will focus on the stellar populations of various "hot spots" along the star burst rings, as well as the galaxy nuclei proper. Using stellar population synthesis methods, we will derive the relative stellar population ages throughout the rings, and check for age gradients along the rings. We will discuss how the results constrain competing theories for the mechanism(s) that govern star formation within resonance rings, and the implications for the morphological evolution of spiral nuclei.