Stellar Kinematics and Dynamical Modeling of Two Seyfert Galaxies

A crucial breakthrough in the study of galaxy evolution occurred with the discovery that black holes are ubiquitous in galaxy nuclei, and the masses of supermassive black holes scale with several properties of the host galaxies. The interpretation is that central black holes and their host galaxies co-evolve and regulate one another’s growth. Although the role supermassive black holes play in galaxy evolution is not fully understood, their mass is a key piece of the puzzle. The most commonly adopted methods for determining supermassive black hole mass are reverberation mapping and stellar dynamical modeling. These two techniques rely on independent assumptions, observational data, and analysis procedures, and are almost always applied to different galaxies. Because of the different requirements for each technique, there are only a handful of galaxies that are candidates for both methods, and so each one plays a critical role in probing elements of the techniques themselves and identifying any systematic biases in the results. Currently, only two supermassive black holes have published masses using both methods. In this work, we present mass measurements of the supermassive black holes in two additional galaxies using stellar dynamical modeling. We first present the kinematic and photometric analysis of the lenticular galaxy NGC5273 and demonstrate that the dynamical models reveal a black hole mass of M• = [0.5 − 2.0]x10^7 M⊙. We then discuss the classical spiral galaxy NGC6814 and derive a black hole mass of M• = [0.5−1.2]x10^7 M⊙ from preliminary models. Both galaxies already have black hole masses measured with reverberation mapping, thus, we are effectively doubling the sample of galaxies for this study. The masses for NGC5273 agree, and the masses for NGC6814 are tentatively in agreement, depending on the scale factor used for the reverberation mass