The Lick AGN Monitoring Project 2016: Dynamical Modeling of Velocity-Resolved H\b{eta} Lags in Luminous Seyfert Galaxies

TL;DR

This study models velocity-resolved Hβ reverberation in nine Seyfert galaxies to infer BLR geometry and black hole masses, revealing a generally thick disk structure with diverse kinematics and no strong luminosity dependence.

Contribution

It provides detailed dynamical modeling of the BLR in multiple Seyfert galaxies, combining new data with prior studies to analyze line-profile and luminosity effects.

Findings

BLR is generally a thick disk viewed at low to moderate inclination.

No strong luminosity-dependent trends in BLR structure.

Marginal anticorrelation between line profile shape and Eddington ratio.

Abstract

We have modeled the velocity-resolved reverberation response of the H\b{eta} broad emission line in nine Seyfert 1 galaxies from the Lick Active Galactic Nucleus (AGN) Monitioring Project 2016 sample, drawing inferences on the geometry and structure of the low-ionization broad-line region (BLR) and the mass of the central supermassive black hole. Overall, we find that the H\b{eta} BLR is generally a thick disk viewed at low to moderate inclination angles. We combine our sample with prior studies and investigate line-profile shape dependence, such as log10(FWHM/{\sigma}), on BLR structure and kinematics and search for any BLR luminosity-dependent trends. We find marginal evidence for an anticorrelation between the profile shape of the broad H\b{eta} emission line and the Eddington ratio, when using the root-mean-square spectrum. However, we do not find any luminosity-dependent trends, and conclude that AGNs have diverse BLR structure and kinematics, consistent with the hypothesis of transient AGN/BLR conditions rather than systematic trends.