Program: GN-2015A-Q-30

We propose to obtain NIFS spatially-resolved spectroscopy of the stellar dynamics in the nucleus of the nearby Seyfert galaxy NGC5273. We will model the nuclear stellar dynamics to determine an independent measurement of the central black hole mass, which we will compare with a recently-obtained reverberation mass. NGC5273 is the only early-type galaxy with a reverberation-based black hole mass that is also close enough to investigate with stellar dynamical modeling. While it is only a single object, NGC5273 can provide the very best comparison between the results of these two independent mass determination techniques and allow us to carry out the fundamental check that all black hole masses are on the same absolute scale. All black hole masses derived at cosmological distances are fundamentally based on reverberation mapping and dynamical modeling of galaxies in the local Universe. The results of this project, therefore, have the ability to impact our entire understanding of black hole and galaxy growth and evolution across the history of the Universe.