Early AGN and Galaxy Formation (Invited paper)

Summary

ABSTRACT

Formation of first AGN probably follows closely the formation of their host galaxies. Both processes may involve similar astrophysical events or processes, with comparable energetics. Young AGN could have had a profound effect on the host galaxies. High–Z AGN may be used as markers of galaxy formation sites, or probes of early large-scale structure. Some may well be examples of galaxies in the early stages of formation, although the nature of their dominant energy sources and their evolutionary status remain ambiguous. Future observations at IR through sub-mm wavelengths lead to a discovery of possible obscured protogalaxies and nascent AGN, and probe their formation at very high z.

INTRODUCTION: FORMATION OF GALAXIES AND AGN

Probably the two key problems in extragalactic astronomy and cosmology today are the understanding of formation and evolution of galaxies and large-scale structure, and the understanding of formation and evolution of AGN. These problems may be fundamentally connected: it is now generally understood that the same kind of astrophysical processes, dissipative merging and infall, may be central to both formation of galaxies and formation of AGN, and subsequently to be contributing both to the simulation of star forming activity in galaxies and to the feeding of their central engines. AGN may also exert a considerable feedback to their host galaxies, and perhaps even determine some of their global properties.