AGN fueling and feedback, from pc to kpc scale

TL;DR

This paper reviews the mechanisms of gas inflow and feedback in active galactic nuclei, highlighting recent high-resolution observations that reveal fueling processes and molecular outflows at scales from 10pc to kpc.

Contribution

It synthesizes recent observational evidence of AGN fueling and feedback mechanisms at small scales, emphasizing the role of molecular outflows and disks in galaxy evolution.

Findings

Detection of molecular outflows with loading factors 1-5.

Evidence of gas fueling at 10pc scale within black hole influence.

Presence of kinematically decoupled molecular tori at 10pc.

Abstract

Dynamical mechanisms are essential to exchange angular momentum in galaxies, drive the gas to the center, and fuel the central super-massive black holes. While at 100pc scale, the gas is sometimes stalled in nuclear rings, recent observations reaching 10pc scale have revealed, within the sphere of influence of the black hole, smoking gun evidence of fueling. Observations of AGN feedback are described, together with the suspected responsible mechanisms. Molecular outflows are frequently detected in active galaxies with ALMA and NOEMA, with loading factors between 1 and 5. When driven by AGN with escape velocity, these outflows are therefore a clear way to moderate or suppress star formation. Molecular disks, or tori, are detected at 10pc-scale, kinematically decoupled from their host disk, with random orientation. They can be used to measure the black hole mass.