Exploring galactic nuclei with tidal disruption events

Tidal disruption events (TDEs) provide a unique opportunity to study the physics of black hole accretion and the stellar populations and dynamics in galactic nuclei. However, constraining the properties of the disrupted star and the accretion efficiency has proven difficult, as these parameters have similar effects on the observed light curve. By combining light curve modeling with spectral line information and knowledge about the stellar populations in the host galaxies, we can independently constrain the properties of the disrupted star for a few of these events. We find that there is an overabundance of stars above ~1-2 solar masses compared to what we would expect from the host galaxies’ stellar populations or our own galactic center. Perhaps the nuclei of these galaxies are forming stars more frequently and at higher rates than the rest of these galaxies, or dynamical processes are increasing the rates of high-mass disruptions. Either way, these results show that TDEs can provide a window into the stellar populations living at the very centers of galaxies, at size scales that we are not able to observe directly outside our closest galactic neighbors.