Evidence for merger-induced AGN fueling using integral field spectroscopy

Hydrodynamical simulations of galaxy mergers have suggested that merger-induced gas-inflows may be able to fuel the central supermassive black hole (SMBH), triggering an active galactic nucleus (AGN). Despite the results of these simulations, observational studies disagree on whether or not there is merger-induced AGN. We use the recently completed integral field spectroscopic (IFS) survey, MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), to study the volume densities and [OIII] luminosities of AGN in paired galaxies. We build a sample of 387 spectroscopically confirmed galaxy pairs of which 102 host an AGN and a sample of 24 dual AGN (dAGN). We find that the volume density of AGN in galaxy pairs is higher than what would be expected by the random pairing of stochastically triggered AGN. At close separations, the volume density of AGN in pairs is 2.5x what is expected from the random pairing of AGN. We further find that the volume density of dAGN under separations of 4 kpc is 40x what we would expect from the random pairing of stochastically triggered AGN. We find that neither correlated AGN activity nor merger-induced fueling can fully explain the excess AGN volume density. Instead, we find that a model that includes stochastic fueling, merger-induced fueling, and correlated AGN activity is required to fully explain the excess AGN in our sample of galaxy pairs. We also find that the AGN in our galaxy pairs feature enhanced levels of [OIII] luminosity in comparison to the AGN in isolated control galaxies to the order of 0.1-0.4 dex. The enhanced volume density and [OIII] luminosity demonstrates the impact that galaxy interactions have on the development of the supermassive black holes (SMBH) found in the centers of galaxies.