Monitoring AGNs with H\beta\ Asymmetry. II. Reverberation Mapping of Three Seyfert Galaxies Historically Displaying H\beta\ Profiles with Changing Asymmetry: Mrk 79, NGC 3227, and Mrk 841

TL;DR

This study uses reverberation mapping to measure black hole masses and analyze the broad line region structures of three Seyfert galaxies, revealing complex gas dynamics and evolution in their emission line profiles.

Contribution

First-time black hole mass estimates for Mrk 841 and detailed velocity-delay maps for Mrk 79 and NGC 3227, showing complex inflow and outflow structures.

Findings

Measured Hβ time lags for all three galaxies.

Detected asymmetric velocity-delay maps indicating complex gas motions.

Observed evolving broad line region structures despite similar luminosities.

Abstract

We report the results of reverberation mapping three bright Seyfert galaxies, Mrk 79, NGC 3227, and Mrk 841, from a campaign conducted from December 2016 to May 2017 with the Wyoming Infrared Observatory (WIRO) 2.3-meter telescope. All three of these targets have shown asymmetric broad H$\beta$ emission lines in the past, although their emission lines were relatively symmetric during our observations. We measured H\beta\ time lags for all three targets and estimated masses of their black holes -- for the first time in the case of Mrk 841. For Mrk 79 and NGC 3227, the data are of sufficient quality to resolve distinct time lags as a function of velocity and to compute two-dimensional velocity-delay maps. Mrk 79 shows smaller time lags for high-velocity gas but the distribution is not symmetric, and its complex velocity-delay map could result from the combination of both inflowing and outflowing H\beta\ emitting disks that may be part of a single larger structure. NGC 3227 shows the largest time lags for blueshifted gas and the two-dimensional velocity-delay map suggests a disk with some inflow. We compare our results with previous work and find evidence for different time lags despite similar luminosities, as well as evolving broad line region structures.