SIMBAD references

We investigate the origin of the intrinsic scatter in the correlation between black hole mass (M_BH) and bulge luminosity (L_bul) in a sample of 45 massive, local (z≲0.35) type 1 active galactic nuclei (AGNs). We derive M_BH from published optical spectra assuming a spherical broad-line region, and L_bul from detailed two-dimensional decomposition of archival optical Hubble Space Telescope images. AGNs follow the M_BH-L_bul relation of inactive galaxies, but the zero point is shifted by an average of ΔlogM_BH~-0.3 dex. We show that the magnitude of the zero point offset, which is responsible for the intrinsic scatter in the M_BH-L_bul relation, is correlated with several AGN and host galaxy properties, all of which are ultimately related to, or directly impact, the BH mass accretion rate. At a given bulge luminosity, sources with higher Eddington ratios have lower M_BH. The zero point offset can be explained by a change in the normalization of the virial product used to estimate M_BH, in conjunction with modest BH growth (∼10%-40%) during the AGN phase. Galaxy mergers and tidal interactions appear to play an important role in regulating AGN fueling in low-redshift AGNs.