Galaxy interactions, and the starburst galaxies - AGN connection.

Abstract

Starbursts and Active Galactic Nuclei (AGN) are observed to preferentially occur in interacting or barred field galaxies. Galaxy interactions cause gas infall from the galactic disks, which may lead to the triggering of a central starburst which could then evolve to an AGN, or the gas infall may fuel a pre-existing central black hole in an AGN. Here, first the concept of galaxy interactions is introduced. Then the problem of fuelling of an AGN is discussed and it is shown that galaxy interactions or bars help in this process. Next, an overview of the physical properties of the starburst galaxies, including their tracers and the triggering mechanisms, is given. Some simple theoretical ideas regarding the physical, causal connection between starbust galaxies and AGN are discussed. Implications of the starburst-AGN connection for the evolution of the high redshift galaxies are mentioned. The current trends and future problems in these topics are briefly discussed.