Tidal Disruption Events from the Combined Effects of Two-body Relaxation and the Eccentric Kozai–Lidov Mechanism
Tidal disruption events (TDEs) take place when a star ventures too close to a supermassive black hole (SMBH) and becomes ruptured. One of the leading proposed physical mechanisms often invoked in the literature involves weak two-body interactions experienced by the population of stars within the hos...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acfee0 |
| _version_ | 1797384788259110912 |
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| author | Denyz Melchor Brenna Mockler Smadar Naoz Sanaea C. Rose Enrico Ramirez-Ruiz |
| author_facet | Denyz Melchor Brenna Mockler Smadar Naoz Sanaea C. Rose Enrico Ramirez-Ruiz |
| author_sort | Denyz Melchor |
| collection | DOAJ |
| description | Tidal disruption events (TDEs) take place when a star ventures too close to a supermassive black hole (SMBH) and becomes ruptured. One of the leading proposed physical mechanisms often invoked in the literature involves weak two-body interactions experienced by the population of stars within the host SMBH’s sphere of influence, commonly referred to as two-body relaxation. This process can alter the angular momentum of stars at large distances and place them into nearly radial orbits, thus driving them to disruption. On the other hand, gravitational perturbations from an SMBH companion via the eccentric Kozai–Lidov (EKL) mechanism have also been proposed as a promising stellar disruption channel. Here we demonstrate that the combination of EKL and two-body relaxation in SMBH binaries is imperative for building a comprehensive picture of the rates of TDEs. Here we explore how the density profile of the surrounding stellar distribution and the binary orbital parameters of an SMBH companion influence the rate of TDEs. We show that this combined channel naturally produces disruptions at a rate that is consistent with observations and also naturally forms repeated TDEs, where a bound star is partially disrupted over multiple orbits. Recent observations show stars being disrupted in short-period orbits, which is challenging to explain when these mechanisms are considered independently. However, the diffusive effect of two-body relaxation, combined with the secular nature of the eccentricity excitations from EKL, is found to drive stars on short eccentric orbits at a much higher rate. Finally, we predict that rTDEs are more likely to take place in the presence of a steep stellar density distribution. |
| first_indexed | 2024-03-08T21:43:44Z |
| format | Article |
| id | doaj.art-150778b23ac4415fa66af90e722fbd74 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T21:43:44Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-150778b23ac4415fa66af90e722fbd742023-12-20T10:37:38ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0196013910.3847/1538-4357/acfee0Tidal Disruption Events from the Combined Effects of Two-body Relaxation and the Eccentric Kozai–Lidov MechanismDenyz Melchor0https://orcid.org/0000-0002-7854-1953Brenna Mockler1https://orcid.org/0000-0001-6350-8168Smadar Naoz2https://orcid.org/0000-0002-9802-9279Sanaea C. Rose3https://orcid.org/0000-0003-0984-4456Enrico Ramirez-Ruiz4https://orcid.org/0000-0003-2558-3102Department of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA ; denyzamelchor@astro.ucla.edu; Mani L. Bhaumik Institute for Theoretical Physics , Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095, USADepartment of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA ; denyzamelchor@astro.ucla.edu; The Observatories of the Carnegie Institution for Science , Pasadena, CA 91101, USADepartment of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA ; denyzamelchor@astro.ucla.edu; Mani L. Bhaumik Institute for Theoretical Physics , Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095, USADepartment of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA ; denyzamelchor@astro.ucla.edu; Mani L. Bhaumik Institute for Theoretical Physics , Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095, USADepartment of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USATidal disruption events (TDEs) take place when a star ventures too close to a supermassive black hole (SMBH) and becomes ruptured. One of the leading proposed physical mechanisms often invoked in the literature involves weak two-body interactions experienced by the population of stars within the host SMBH’s sphere of influence, commonly referred to as two-body relaxation. This process can alter the angular momentum of stars at large distances and place them into nearly radial orbits, thus driving them to disruption. On the other hand, gravitational perturbations from an SMBH companion via the eccentric Kozai–Lidov (EKL) mechanism have also been proposed as a promising stellar disruption channel. Here we demonstrate that the combination of EKL and two-body relaxation in SMBH binaries is imperative for building a comprehensive picture of the rates of TDEs. Here we explore how the density profile of the surrounding stellar distribution and the binary orbital parameters of an SMBH companion influence the rate of TDEs. We show that this combined channel naturally produces disruptions at a rate that is consistent with observations and also naturally forms repeated TDEs, where a bound star is partially disrupted over multiple orbits. Recent observations show stars being disrupted in short-period orbits, which is challenging to explain when these mechanisms are considered independently. However, the diffusive effect of two-body relaxation, combined with the secular nature of the eccentricity excitations from EKL, is found to drive stars on short eccentric orbits at a much higher rate. Finally, we predict that rTDEs are more likely to take place in the presence of a steep stellar density distribution.https://doi.org/10.3847/1538-4357/acfee0Supermassive black holesTidal disruptionBlack holesEccentricityOrbital evolution |
| spellingShingle | Denyz Melchor Brenna Mockler Smadar Naoz Sanaea C. Rose Enrico Ramirez-Ruiz Tidal Disruption Events from the Combined Effects of Two-body Relaxation and the Eccentric Kozai–Lidov Mechanism The Astrophysical Journal Supermassive black holes Tidal disruption Black holes Eccentricity Orbital evolution |
| title | Tidal Disruption Events from the Combined Effects of Two-body Relaxation and the Eccentric Kozai–Lidov Mechanism |
| title_full | Tidal Disruption Events from the Combined Effects of Two-body Relaxation and the Eccentric Kozai–Lidov Mechanism |
| title_fullStr | Tidal Disruption Events from the Combined Effects of Two-body Relaxation and the Eccentric Kozai–Lidov Mechanism |
| title_full_unstemmed | Tidal Disruption Events from the Combined Effects of Two-body Relaxation and the Eccentric Kozai–Lidov Mechanism |
| title_short | Tidal Disruption Events from the Combined Effects of Two-body Relaxation and the Eccentric Kozai–Lidov Mechanism |
| title_sort | tidal disruption events from the combined effects of two body relaxation and the eccentric kozai lidov mechanism |
| topic | Supermassive black holes Tidal disruption Black holes Eccentricity Orbital evolution |
| url | https://doi.org/10.3847/1538-4357/acfee0 |
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