Title: The Mass of the Central Black Hole in the Nearby Seyfert Galaxy NGC5273 Author: Misty C. Bentz (Georgia State University), Daniel Horenstein, Craig Bazhaw, Emily R. Manne-Nicholas, Benjamin J. Ou-Yang, Matthew Anderson, Jeremy Jones, Ryan P. Norris, J. Robert Parks, Dicy Saylor, Katherine G. Teems, Clay Turner
We present the results of a reverberation-mapping program targeting NGC5273, a nearby early-type galaxy with a broad-lined active galactic nucleus. Over the course of the monitoring program, NGC5273 showed strong variability that allowed us to measure time delays in the responses of the broad optical recombination lines to changes in the continuum flux. A weighted average of these measurements results in a black hole mass determination of MBH=(4.7±1.6) x 10^6 solar masses. An estimate of the size of the black hole sphere of influence in NGC5273 puts it just at the limit of the resolution achievable with current ground-based large aperture telescopes. NGC5273 is therefore an important future target for a black hole mass determination from stellar dynamical modelling, especially because it is the only nearby early-type galaxy hosting an AGN with a reverberation-based mass, allowing the best comparison for the masses determined from these two techniques.