Institute for Advanced Study Informal Astrophysics Seminar

In this talk I will present results on the study of circumnuclear star-forming rings based on integral-field SAURON and NIR SINFONI observations. I'll review the main kinematic properties of these features and their relation to the surrounding morphological structures. Also, I will show that making use of the relative intensities of different NIR emission lines (i.e. [FeII], HeI, Brg) it is possible to age date the stellar clusters in the rings and therefore describe the preferred way star formation progresses along them. The main emphasis of the talk, however, I will be on the nuclear spectrum of one of the galaxies in the sample (NGC0613) to show that it is dominated by H2 and [FeII] emission, but with very little signatures of current star formation. I will make use of the line ratios of the emission lines present in our H- and K-band spectrum to discuss whether gas is accumulating in the nucleus and it is in a pre-starburst phase or whether, in contrast, the H2 and [FeII] lines are produced by a known AGN whose outflow is currently disturbing the surrounding star-forming ring.