The Relation between the Large-scale Gas Dynamics, Nuclear Kinematics, and Activity in Spiral Galaxies

(1996), in ``The Minnesota Lectures on Extragalactic Neutral Hydrogen'',
ASP Conf. Series Vol. 106, ed. Evan D. Skillman, p. 238

The Relation between the Large-scale Gas Dynamics,
Nuclear Kinematics, and Activity in Spiral Galaxies

Australia Telescope National Facility (CSIRO), P.O.Box 76, Epping, NSW 2121, Australia

Abstract:

Most of the spirals discussed in the following are well-known starburst galaxies (M 82, NGC 253, etc.). In addition to their nuclear activity, which makes them so popular, the selected galaxies have several other phenomena in common, such as bars, gas outflow, and possibly nuclear rings. The relationship between those phenomena is discussed in the following. I will show that the gas dynamics in the outer and inner parts of these galaxies are strongly related to their starburst activity. Galaxy interactions as well as bars play an important role as they affect the gas flow within the disk, driving gas inwards and outwards where it accumulates at preferred resonance orbits. The inflowing gas provides the supply for the central starburst region from which gas is eventually ejected into the halo. I compare the group of nearby starburst galaxies with distant ultra-luminous galaxies (Arp 220, NGC 6240, etc.), in which strong tidal interactions cause the radial gas inflow. In both groups high-resolution HI absorption measurements reveal fast-rotating nuclear rings.