DO QUIESCENT AND ACTIVE GALAXIES HAVE DIFFERENTM_BH-σ_*RELATIONS?

Abstract

To investigate the validity of the assumption that quiescent galaxies and active galaxies follow the same black hole mass (M BH )-stellar velocity dispersion (σ * ) relation, as required for the calibration of M BH estimators for broad line AGNs, we determine and compare the M BH -σ * relations, respectively, for quiescent and active galaxies. For the quiescent galaxy sample, composed of 72 dynamical M BH measurements, we update σ * for 28 galaxies using homogeneous H-band measurements that are corrected for galaxy rotation. For active galaxies, we collect 25 reverberation-mapped AGNs and improve σ * measurement for two objects . Combining the two samples, we determine the virial factor f , first by scaling the active galaxy sample to the M BH -σ * relation of quiescent galaxies, and second by simultaneously fitting the quiescent and active galaxy samples, as f = 5.1 +1.5 −1.1 and f = 5.9 +2.1 −1.5 , respectively. The M BH -σ * relation of active galaxies appears to be shallower than that of quiescent galaxies. However, the discrepancy is caused by a difference in the accessible M BH distribution at given σ * , primarily due to the difficulty of measuring reliable stellar velocity dispersion for the host galaxies of luminous AGNs. Accounting for the selection effects, we find that active and quiescent galaxies are consistent with following intrinsically the same M BH -σ * relation.

Detection of faint broad emission lines in type 2 AGNs – III. On the MBH-σ⋆ relation of type 2 AGNs

“…For comparison, the residual of the relation of Kormendy & Ho (2013, solid grey line) is also reported. As the relation of Woo et al (2013) is the reference for the calibration of the f -factor 4.31 that we are using, the average residual in BH mass (0.00 ± 0.09) and stellar velocity dispersions (0.00 ± 0.02) in the RM AGN1 are, as expected, consistent with zero. On the contrary, the average residual for AGN2 is ∆ log M BH = −0.99 ± 0.37 or equivalently ∆ log σ ⋆ = 0.14 ± 0.04.…”

“…Table 1 lists the general properties of the final sample of 13 AGN2 with measured σ ⋆ and virial BH masses, which have all been calculated with solution a3 of Table 4 of Ricci et al (2017) assuming an average virial factor f = 4.31. This virial factor has been derived by Grier et al (2013) by requiring that RM AGN1 reproduce the M BH − σ ⋆ relation found in quiescent galaxies by Woo et al (2013). In all the following analyses, we excluded Table 1.…”

“…The bottom and right panels of Figure 2 report the residuals in BH masses ∆ log M BH and stellar velocity dispersions ∆ log σ ⋆ . The BH masses residuals are computed as the logarithmic difference between the virially measured M BH and that expected from the scaling relation of Woo et al (2013). For comparison, the residual of the relation of Kormendy & Ho (2013, solid grey line) is also reported.…”

The cosmic growth of the active black hole population at 1 <z <2 in zCOSMOS, VVDS and SDSS

“…This method employs the virial relation M• = f RBLR∆V 2 /G, where the broad line cloud velocity ∆V is derived from the broad emission line width, f is a scale factor that accounts for the geometry and kinematics of the BLR (usually calibrated by scaling to the local M• −σ * relationship (e.g. Onken et al 2004;Woo et al 2010;Woo et al 2013), and RBLR is the broad line region size. While the latter can be directly measured via reverberation mapping (e.g.…”

A low-luminosity type-1 QSO sample

“…We use their measurements for L 5100 and σ Hβ and apply the recent scale factor f = 5.9 for active galaxies (Woo et al 2013). The resulting black hole mass for HE 1029-1831 is log(M BH /M ) = 7.4.…”