The Lick AGN Monitoring Project 2011: Dynamical Modeling of the Broad-Line Region in Mrk 50

Abstract

We present dynamical modeling of the broad- line region (BLR) in the Seyfert 1 galaxy Mrk 50 using reverberation mapping data taken as part of the Lick AGN Monitoring Project (LAMP) 2011. We model the reverberation mapping data directly, constraining the geometry and kinematics of the BLR, as well as deriving a black hole mass estimate that does not depend on a normalizing factor or virial coefficient. We find that the geometry of the BLR in Mrk 50 is a nearly face-on thick disk, with a mean radius of 9.6(-0.9)(+1.2) light days, a width of the BLR of 6.9(-1.1)(+1.2) light days, and a disk opening angle of 25 +/- 10 deg above the plane. We also constrain the inclination angle to be 9(-5)(+7) deg, close to face-on. Finally, the black hole mass of Mrk 50 is inferred to be log(10)(M-BH/M-circle dot) = 7.57(-0.27)(+0.44). By comparison to the virial black hole mass estimate from traditional reverberation mapping analysis, we find the normalizing constant (virial coefficient) to be log(10) f = 0.78(-0.27)(+0.44), consistent with the commonly adopted mean value of 0.74 based on aligning the M-BH-sigma* relation for active galactic nuclei and quiescent galaxies. While our dynamical model includes the possibility of a net inflow or outflow in the BLR, we cannot distinguish between these two scenarios.