The Mass of the Black Hole in NGC 5273 from Stellar Dynamical Modeling

TL;DR

This study accurately measures the black hole mass in NGC 5273 using stellar dynamical modeling, combining high-resolution imaging and spectroscopy, and compares it with reverberation mapping results.

Contribution

It provides a new black hole mass estimate for NGC 5273 through advanced dynamical modeling, integrating multiple observational data sources.

Findings

Black hole mass estimated at (0.5-2) x 10^7 solar masses.

Mass estimate aligns with reverberation mapping within uncertainties.

Demonstrates the effectiveness of combined AO-assisted and archival data for dynamical modeling.

Abstract

We present a new constraint on the mass of the black hole in the active S0 galaxy NGC 5273. Due to the proximity of the galaxy at $16.6 \pm 2.1$ Mpc, we were able to resolve and extract the bulk motions of stars near the central black hole using AO-assisted observations with Gemini NIFS, as well as constrain the large-scale kinematics using re-reduced archival SAURON spectroscopy. High resolution HST imaging allowed us to generate a surface brightness decomposition, determine approximate mass-to-light ratios for the bulge and disk, and obtain an estimate for the disk inclination. We constructed an extensive library of dynamical models using the Schwarzschild orbit-superposition code FORSTAND, exploring a range of disk and bulge shapes, halo masses, etc. We determined a black hole mass of $M_{\bullet} = [0.5 - 2] \times 10^{7}$ $M_{\odot}$, where the low side of the range is in agreement with the reverberation mapping measurement of $M_{\bullet} = [4.7 \pm 1.6] \times 10^{6}$ $M_{\odot}$. NGC 5273 is one of only a small number of nearby galaxies hosting broad-lined AGN, allowing crucial comparison of the black hole masses derived from different mass measurement techniques.