TY - JOUR
T1 - Partial Tidal Disruptions of Main-sequence Stars by Intermediate-mass Black Holes
AU - Kıroğlu, Fulya
AU - Lombardi, James C.
AU - Kremer, Kyle
AU - Fragione, Giacomo
AU - Fogarty, Shane
AU - Rasio, Frederic A.
N1 - Funding Information:
We would like to thank the anonymous referee for insightful suggestions. We also thank Elena González Prieto for useful discussions. F.K. acknowledges support from a CIERA Board of Visitors Graduate Fellowship. K.K. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under the award AST-2001751. G.F. acknowledges support from NASA grant No. 80NSSC21K1722. This work was supported by NSF grant No. AST-2108624 and NASA ATP grant No. 80NSSC22K0722 at Northwestern University. We thank Byron Rich for helping to prepare workstations at Allegheny College, purchased with a grant from the George I. Alden Trust, to run several of the simulations of this paper.
Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/5/1
Y1 - 2023/5/1
N2 - We study close encounters of a 1 M ⊙ middle-age main-sequence star (modeled using MESA) with massive black holes through hydrodynamic simulations, and explore in particular the dependence of the outcomes on the black hole mass. We consider here black holes in the intermediate-mass range, M BH = 100-104 M ⊙. Possible outcomes vary from a small tidal perturbation for weak encounters all the way to partial or full disruption for stronger encounters. We find that stronger encounters lead to increased mass loss at the first pericenter passage, in many cases ejecting the partially disrupted star on an unbound orbit. For encounters that initially produce a bound system, with only partial stripping of the star, the fraction of mass stripped from the star increases with each subsequent pericenter passage and a stellar remnant of finite mass is ultimately ejected in all cases. The critical penetration depth that separates bound and unbound remnants has a dependence on the black hole mass when M BH ≲ 103 M ⊙. We also find that the number of successive close passages before ejection decreases as we go from the stellar-mass black hole to the intermediate-mass black hole regime. For instance, after an initial encounter right at the classical tidal disruption limit, a 1 M ⊙ star undergoes 16 (5) pericenter passages before ejection from a 10 M ⊙ (100 M ⊙) black hole. Observations of periodic flares from these repeated close passages could in principle indicate signatures of a partial tidal disruption event.
AB - We study close encounters of a 1 M ⊙ middle-age main-sequence star (modeled using MESA) with massive black holes through hydrodynamic simulations, and explore in particular the dependence of the outcomes on the black hole mass. We consider here black holes in the intermediate-mass range, M BH = 100-104 M ⊙. Possible outcomes vary from a small tidal perturbation for weak encounters all the way to partial or full disruption for stronger encounters. We find that stronger encounters lead to increased mass loss at the first pericenter passage, in many cases ejecting the partially disrupted star on an unbound orbit. For encounters that initially produce a bound system, with only partial stripping of the star, the fraction of mass stripped from the star increases with each subsequent pericenter passage and a stellar remnant of finite mass is ultimately ejected in all cases. The critical penetration depth that separates bound and unbound remnants has a dependence on the black hole mass when M BH ≲ 103 M ⊙. We also find that the number of successive close passages before ejection decreases as we go from the stellar-mass black hole to the intermediate-mass black hole regime. For instance, after an initial encounter right at the classical tidal disruption limit, a 1 M ⊙ star undergoes 16 (5) pericenter passages before ejection from a 10 M ⊙ (100 M ⊙) black hole. Observations of periodic flares from these repeated close passages could in principle indicate signatures of a partial tidal disruption event.
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U2 - 10.3847/1538-4357/acc24c
DO - 10.3847/1538-4357/acc24c
M3 - Article
AN - SCOPUS:85159150958
SN - 0004-637X
VL - 948
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 89
ER -