The <i>M</i>_•–<i>σ</i>_<i>e</i> relation for local type 1 AGNs and quasars

We analyzed Multi Unit Spectroscopic Explorer observations of 42 local z ≲ 0.1 type 1 active galactic nucleus (AGN) host galaxies taken from the Palomar-Green quasar sample and the close AGN reference survey. Our goal was to study the relation between the black hole mass ( M • ) and bulge stellar velocity dispersion ( σ e ) for type 1 active galaxies. The sample spans black hole masses of 10 6.0 − 10 9.2 M ⊙ , bolometric luminosities of 10 42.9 − 10 46.0 erg s −1 , and Eddington ratios of 0.006 − 1.2. We avoided AGN emission by extracting the spectra over annular apertures. We modeled the calcium triplet stellar features and measured stellar velocity dispersions of σ * = 60 − 230 km s −1 for the host galaxies. We find stellar velocity dispersion values in agreement with previous measurements for local ( z ≲ 0.1) AGN host galaxies, but slightly lower compared with those reported for nearby X-ray-selected type 2 quasars. Using a novel annular aperture correction recipe to estimate σ e from σ * that considers the bulge morphology and observation beam-smearing, we estimate flux-weighted σ e = 60 − 250 km s −1 . If we consider the bulge type when estimating M • , we find no statistical difference between the distributions of AGN hosts and the inactive galaxies on the M • – σ e plane for M • ≲ 10 8 M ⊙ . Conversely, if we do not consider the bulge type when computing M • , we find that both distributions disagree. We find no correlation between the degree of offset from the M • – σ e relation and Eddington ratio for M • ≲ 10 8 M ⊙ . The current statistics preclude firm conclusions from being drawn for the high-mass range. We argue these observations support notions that a significant fraction of the local type 1 AGNs and quasars have undermassive black holes compared with their host galaxy bulge properties.