Astronomy and astrophysics

Star formation in the central regions of galaxies

by Johan Knapen (IAC and University of Hertfordshire)

Europe/Stockholm
FA31 (AlbaNova)

FA31

AlbaNova

Roslagstullsbacken 21
Description

Massive star formation occurs in the central regions of many spiral galaxies, and often takes the form of a starburst or nuclear ring. In this talk, I will explore relations between the morphology and properties of the central star formation with host galaxy parameters, focussing on the role of bars and interactions.

I will describe a number of detailed investigations of nuclear rings, using the power of modern spectroscopic and imaging techniques in combination with stellar population and emission line modelling. In M100, we find evidence for the presence of relatively cold gas in the ring, which we interpret as material newly brought in from the disk, through the bar, and which fuels the star formation. We discuss the star formation history of the ring and underlying bulge/disk and relate the results to our current picture of the dynamics of nuclear rings and galactic bars.

I then discuss the nuclear ring in the un-barred galaxy NGC 7742, which we use as a showcase for our ability to determine the physical parameters, including the metallicity, from integral-field spectroscopy.

This leads to a picture in which a past minor merger is responsible for the formation and fuelling of the star-forming nuclear ring.