AGN Winds and Nuclear Starbursts (Poster paper)

Summary

This contribution considers the consequences of an active nucleus (AGN) inside a galaxy with a nuclear starburst. General arguments suggest that many AGN generate supersonic winds (Smith 1993a, see also Voit et al. 1993) with velocities v_w ∼ 0.1 v_o.1^c, and the interaction of such a wind with a surrounding starburst is considered below. The large number of quasars indicate that some starburst galaxies should contain the remnant black holes of these “dead” AGN. Even if fueled by only a small amount of gas, the resulting AGN wind can have a significant effect on starburst hydrodynamics.

Note that it is unlikely that a black hole (BH) and subsequent AGN could form due to accretion during the lifetime (10τ₁₀ Myr) of the starburst. Since Eddington limited accretion has a timescale of ∼ 500 Myr, a seed black hole would have to accrete at a rate greater than ∼ 50/τ₁₀ times the Eddington rate to grow substantially.

Mass and energy injection by the supernovae and stellar winds of the starburst will form an outflowing wind. A nuclear wind produced by the AGN will evacuate the central region out to the radius where the mass flux injected by the starburst activity is greater than the mass flux in the nuclear wind. At this point the nuclear wind becomes mass loaded, subsonic, and will merge into the developing starburst wind (Smith 1993b). For a uniform starburst the nuclear wind (with kinetic luminosity will become mass loaded at a radius is the starburst mass injection rate, parameterized as the supernova rate times the mass injected per supernova (including stellar winds).