Host galaxy properties of changing-look AGNs revealed in the MaNGA survey

Abstract

Changing-look active galactic nuclei (CL-AGNs) are a subset of AGNs in which the broad Balmer emission lines appear or disappear within a few years. We use the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey to identify five CL-AGNs. The 2D photometric and kinematic maps reveal common features as well as some unusual properties of CL-AGN hosts as compared to the AGN hosts in general. All MaNGA CL-AGNs reside in the star-forming main sequence, similar to MaNGA non-changing-look AGNs (NCL-AGNs). The 80 ± 16 per cent of our CL-AGNs do possess pseudo-bulge features, and follow the overall NCL-AGN MBH–σ∗ relationship. The kinematic measurements indicate that they have similar distributions in the plane of angular momentum versus galaxy ellipticity. MaNGA CL-AGNs, however, show a higher, but not statistically significant (20 ± 16 per cent) fraction of counter-rotating features compared to that (1.84 ± 0.61 per cent) in general star formation population. In addition, MaNGA CL-AGNs favour more face-on (axial ratio > 0.7) than that of type I NCL-AGNs. These results suggest that host galaxies could play a role in the CL-AGN phenomenon.