The first 62 AGN observed with SDSS-IV MaNGA - II. Resolved stellar populations

Abstract

We present spatially resolved stellar population (SP) age maps, average radial profiles and gradients for the first 62 active galactic nuclei (AGN) observed with Sloan Digital Sky Survey (SDSS)-IV Mapping Nearby Galaxies at Apache Point Observatory (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 SPs in highluminosity AGN is higher in the inner (R ≤ 0.5 Re) 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 Re). 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 ≤ 40 Myr) in the central region.