An IFU View of the Active Galactic Nuclei in MaNGA Galaxy Pairs
  The role of active galactic nuclei (AGNs) during galaxy interactions and how
they influence the star formation in the system are still under debate. We use
a sample of 1156 galaxies in galaxy pairs or mergers (hereafter `pairs') from
the MaNGA survey. This pair sample is selected by the velocity offset,
projected separation, and morphology, and is further classified into four cases
along the merger sequence based on morphological signatures. We then identify a
total of 61 (5.5%) AGNs in pairs based on the emission-line diagnostics. No
evolution of the AGN fraction is found, either along the merger sequence or
compared to isolated galaxies (5.0%). We observe a higher fraction of passive
galaxies in galaxy pairs, especially in the pre-merging cases, and associate
the higher fraction to their environmental dependence. The isolated AGN and AGN
in pairs show similar distributions in their global stellar mass, star
formation rate (SFR), and central [OIII] surface brightness. AGNs in pairs show
radial profiles of increasing specific SFR and declining Dn4000 from center to
outskirts, and no significant difference from the isolated AGNs. This is
clearly different from star-forming galaxies (SFGs) in our pair sample, which
show enhanced central star formation, as reported before. AGNs in pairs have
lower Balmer decrements at outer regions, possibly indicating less dust
attenuation. Our findings suggest that AGNs likely follow an inside-out
quenching and the merger impact on the star formation in AGNs is less prominent
than in SFGs.
