Partial stellar tidal disruption events and their rates
Abstract
Tidal disruption events (TDEs) of stars operated by massive black holes (MBHs) will be detected in thousands by upcoming facilities such as the Vera Rubin Observatory. In this work, we assess the rates of standard total TDEs, destroying the entire star, and partial TDEs, in which a stellar remnant survives the interaction, by solving 1D FokkerPlanck equations. Our rate estimates are based on a novel definition of the loss cone whose size is commensurate with the largest radius at which partial disruptions can occur, as motivated by relativistic hydrodynamical simulations. Our novel approach unveils two important results. First, partial TDEs can be more abundant than total disruptions by a factor of a few to a few tens. Second, the rates of complete stellar disruptions can be overestimated by a factor of a few to a few tens if one neglects partial TDEs, as we find that many of the events classified as total disruptions in the standard framework are in fact partial TDEs. Accounting for partial TDEs is particularly relevant for galaxies harbouring a nuclear stellar cluster featuring many events coming from the empty loss cone. Based on these findings, we stress that partial disruptions should be considered when constraining the luminosity function of TDE flares; accounting for this may reconcile the theoretically estimated TDE rates with the observed ones.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 September 2023
 DOI:
 10.1093/mnras/stad2024
 arXiv:
 arXiv:2303.03408
 Bibcode:
 2023MNRAS.524.3026B
 Keywords:

 black hole physics;
 methods: numerical;
 stars: kinematics and dynamics;
 galaxies: kinematics and dynamics;
 transients: tidal disruption events;
 Astrophysics  High Energy Astrophysical Phenomena;
 Astrophysics  Astrophysics of Galaxies;
 Astrophysics  Instrumentation and Methods for Astrophysics;
 Astrophysics  Solar and Stellar Astrophysics;
 85A05
 EPrint:
 12 pages + Appendix, MNRAS, accepted