English

Wind-Reprocessed Transients from Stellar-mass Black Hole Tidal Disruption Events

High Energy Astrophysical Phenomena 2023-08-09 v2 Astrophysics of Galaxies Solar and Stellar Astrophysics

Abstract

Tidal disruptions of stars by stellar-mass black holes are expected to occur frequently in dense star clusters. Building upon previous studies that performed hydrodynamic simulations of these encounters, we explore the formation and long-term evolution of the thick, super-Eddington accretion disks formed. We build a disk model that includes fallback of material from the tidal disruption, accretion onto the black hole, and disk mass losses through winds launched in association with the super-Eddington flow. We demonstrate that bright transients are expected when radiation from the central engine powered by accretion onto the black hole is reprocessed at large radii by the optically-thick disk wind. By combining hydrodynamic simulations of these disruption events with our disk+wind model, we compute light curves of these wind-reprocessed transients for a wide range of stellar masses and encounter penetration depths. We find typical peak bolometric luminosities of roughly 1041104410^{41}-10^{44}\,erg/s (depending mostly on accretion physics parameters) and temperatures of roughly 10510610^5-10^6\,K, suggesting peak emission in the ultraviolet/blue bands. We predict all-sky surveys such as the Vera Rubin Observatory and ULTRASAT will detect up to thousands of these events per year in dense star clusters out to distances of several Gpc.

Keywords

Cite

@article{arxiv.2305.08905,
  title  = {Wind-Reprocessed Transients from Stellar-mass Black Hole Tidal Disruption Events},
  author = {Kyle Kremer and Brenna Mockler and Anthony L. Piro and James C. Lombardi},
  journal= {arXiv preprint arXiv:2305.08905},
  year   = {2023}
}

Comments

16 Pages, 13 figures, 2 tables. Accepted for publication in MNRAS