Wind-Reprocessed Transients from Stellar-mass Black Hole Tidal Disruption Events
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 $10^{41}-10^{44}\,$erg/s (depending mostly on accretion physics parameters) and temperatures of roughly $10^5-10^6\,$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.
- Publication:
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arXiv e-prints
- Pub Date:
- May 2023
- DOI:
- 10.48550/arXiv.2305.08905
- arXiv:
- arXiv:2305.08905
- Bibcode:
- 2023arXiv230508905K
- Keywords:
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- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 16 Pages, 13 figures, 2 tables. Submitted to MNRAS. Comments welcome!