Recalibration of the MBH–σ⋆ Relation for AGN

We present a re-calibration of the $M_{BH}-\sigma_{\star}$ relation for AGN, based on a sample of 16 reverberation-mapped galaxies with newly determined bulge stellar velocity dispersions ($\sigma_{\star}$) from integral-field (IFU) spectroscopy. IFU spectroscopy provides a spatially resolved view of the stellar kinematics within the bulge of each target galaxy, from which significantly improved $\sigma_{\star}$ determinations can be made. This method accounts for variations in the stellar kinematics resulting from the presence of substructure (e.g.\ bars), and avoids many of the biases that are known to be present in long slit and single aperture spectroscopy. The sample covers three orders of magnitude in black hole mass, and is approximately evenly split between early- and late-type galaxies, and barred and unbarred galaxies. We find a best fitting slope of $\beta=3.77\pm0.99$ for the full sample, which is consistent with recent estimates of the relation for active galaxies, and shallower than recent estimates of the relation for quiescent galaxies. We find that our best-fit relationship is not sensitive to galaxy morphology. We recalculate the virial scaling factor $f$ required to bring the reverberation-mapped AGN sample into agreement with the fit for quiescent galaxies, and find $f=3.39\pm1.28$.