The first 62 AGN observed with SDSS-IV MaNGA - II: resolved stellar populations

TL;DR

This study uses spatially resolved stellar population maps from SDSS-IV MaNGA to compare AGN host galaxies with non-active ones, revealing that high-luminosity AGN are associated with recent central star formation likely triggered by gas inflow.

Contribution

First spatially resolved analysis of stellar populations in AGN hosts using MaNGA data, highlighting differences based on AGN luminosity and host galaxy type.

Findings

High-luminosity AGN have more young stars in the center compared to controls.

Low-luminosity AGN show similar stellar populations to control galaxies.

Recent gas inflow likely triggers star formation in luminous AGN hosts.

Abstract

We present spatially resolved stellar population age maps, average radial profiles and gradients for the first 62 Active Galactic Nuclei (AGN) observed with SDSS-IV MaNGA to study the effects of the active nuclei on the star formation history of the host galaxies. These results, derived using the STARLIGHT code, are compared with a control sample of non-active galaxies matching the properties of the AGN hosts. We find that the fraction of young stellar populations (SP) in high-luminosity AGN is higher in the inner ($R \leq 0.5\,R_e$) regions when compared with the control sample; low-luminosity AGN, on the other hand, present very similar fractions of young stars to the control sample hosts for the entire studied range ($1\,R_e$). The fraction of intermediate age SP of the AGN hosts increases outwards, with a clear enhancement when compared with the control sample. The inner region of the galaxies (AGN and control galaxies) presents a dominant old SP, whose fraction decreases outwards. We also compare our results (differences between AGN and control galaxies) for the early and late-type hosts and find no significant differences. In summary, our results suggest that the most luminous AGN seems to have been triggered by a recent supply of gas that has also triggered recent star formation ($t\,\leq\,40\,Myrs$) in the central region.