[The Impact of Nuclear Star Formation on Gas Inflow to AGN

TL;DR

This paper investigates how recent nuclear star formation influences gas inflow to active galactic nuclei, combining observations, analytical models, and simulations to understand the regulation of accretion processes.

Contribution

It introduces a comprehensive model linking stellar evolution, supernova feedback, and gas inflow regulation in AGN environments.

Findings

Supernovae delay gas accretion by generating starburst winds.

Clumpy interstellar medium facilitates inward stellar outflows.

Dense turbulent disks form on parsec scales, reconciling different observational scales.

Abstract

Our adaptive optics observations of nearby AGN at spatial resolutions as small as 0.085arcsec show strong evidence for recent, but no longer active, nuclear star formation. We begin by describing observations that highlight two contrasting methods by which gas can flow into the central tens of parsecs. Gas accumulation in this region will inevitably lead to a starburst, and we discuss the evidence for such events. We then turn to the impact of stellar evolution on the further inflow of gas by combining a phenomenological approach with analytical modelling and hydrodynamic 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 VLTI.