The Lick AGN Monitoring Project 2016: Velocity-Resolved H{\beta} Lags in Luminous Seyfert Galaxies

TL;DR

This study presents velocity-resolved Hβ lag measurements for 21 luminous Seyfert galaxies, revealing diverse BLR gas kinematics and improving black hole mass estimates, thereby enhancing understanding of AGN structure and dynamics.

Contribution

First velocity-resolved Hβ lag measurements for luminous Seyfert galaxies, expanding data on BLR kinematics and refining black hole mass calibration methods.

Findings

Diverse BLR gas kinematics observed at high luminosity.

Hβ lag times range from 8 to 30 days.

Black hole masses estimated between 10^7.1 and 10^8.1 Msun.

Abstract

We carried out spectroscopic monitoring of 21 low-redshift Seyfert 1 galaxies using the Kast double spectrograph on the 3-m Shane telescope at Lick Observatory from April 2016 to May 2017. Targeting active galactic nuclei (AGN) with luminosities of {\lambda}L{\lambda} (5100 {\AA}) = 10^44 erg/s and predicted H{\beta} lags of 20-30 days or black hole masses of 10^7-10^8.5 Msun, our campaign probes luminosity-dependent trends in broad-line region (BLR) structure and dynamics as well as to improve calibrations for single-epoch estimates of quasar black hole masses. Here we present the first results from the campaign, including H{\beta} emission-line light curves, integrated H{\beta} lag times (8-30 days) measured against V-band continuum light curves, velocity-resolved reverberation lags, line widths of the broad H{\beta} components, and virial black hole mass estimates (10^7.1-10^8.1 Msun). Our results add significantly to the number of existing velocity-resolved lag measurements and reveal a diversity of BLR gas kinematics at moderately high AGN luminosities. AGN continuum luminosity appears not to be correlated with the type of kinematics that its BLR gas may exhibit. Follow-up direct modeling of this dataset will elucidate the detailed kinematics and provide robust dynamical black hole masses for several objects in this sample.