Weighing Black Holes using Tidal Disruption Events

Abstract: While once rare, observations of stars being tidally disrupted by supermassive black holes are quickly becoming commonplace. To continue to learn from these events it is necessary to robustly and systematically compare our growing number of observations with theory. We present a tidal disruption module for the Modular Open Source Fitter for Transients (MOSFiT) and the results from fitting 14 tidal disruption events (TDEs). Our model uses FLASH simulations of TDEs to generate bolometric luminosities and passes these luminosities through viscosity and reprocessing transformation functions to create multi-wavelength light curves. It then uses an MCMC fitting routine to compare these theoretical light curves with observations. We find that none of the events show evidence for viscous delays exceeding a few days, supporting the theory that our current observing strategies in the optical/UV are missing a significant number of viscously delayed flares. We find that the events have black hole masses of $10^6 - 10^8 M_{\odot}$, and that the masses we predict are as reliable as those based on bulk galaxy properties. We also find that there is a preference for stars with mass $< 1 M_{\odot}$, as expected when low-mass stars greatly outnumber high-mass stars.