Heidelberg Joint Astronomical Colloquium

Speaker Richard Davies
Title Star formation in the central regions of AGN

Adaptive optics observations of nearby AGN, at spatial resolutions as small as 0.085", show strong evidence for recent–but no longer active– star formation that has occurred in very dense thick nuclear disks. I discuss the impact of stellar evolution on the inflow of gas to fuel the AGN by combining a phenomenological approach with analytical modelling and hydrodynamical simulations. These complementary perspectives paint a picture in which all the processes are ultimately regulated by the mass accretion rate into the central hundred parsecs, and the ensuing starburst that occurs there. The resulting supernovae delay accretion by generating a starburst wind, which leaves behind a clumpy interstellar medium. This provides an ideal environment for slower stellar outflows to accrete inwards and form a dense turbulent disk on scales of a few parsecs. Such a scenario may resolve the discrepancy between the larger scale structure seen with adaptive optics and the small-scale structure seen with the VLTI.