Black hole discs and spheres in galactic nuclei – exploring the landscape of vector resonant relaxation equilibria
Vector resonant relaxation (VRR) is known to be the fastest gravitational process that shapes the geometry of stellar orbits in nuclear star clusters. This leads to the realignment of the orbital planes on the corresponding VRR time-scale tVRR of a few million years, while the eccentricity e and sem...
| Główni autorzy: | , , |
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| Format: | Journal article |
| Język: | English |
| Wydane: |
Oxford University Press
2023
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| _version_ | 1826309858435006464 |
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| author | Máthé, G Szölgyén, Á Kocsis, B |
| author_facet | Máthé, G Szölgyén, Á Kocsis, B |
| author_sort | Máthé, G |
| collection | OXFORD |
| description | Vector resonant relaxation (VRR) is known to be the fastest gravitational process that shapes the geometry of stellar orbits in nuclear star clusters. This leads to the realignment of the orbital planes on the corresponding VRR time-scale tVRR of a few million years, while the eccentricity e and semimajor axis a of the individual orbits are approximately conserved. The distribution of orbital inclinations reaches an internal equilibrium characterized by two conserved quantities, the total potential energy among stellar orbits, Etot, and the total angular momentum, Ltot. On time-scales longer than tVRR, the eccentricities and semimajor axes change slowly, and the distribution of orbital inclinations are expected to evolve through a series of VRR equilibria. Using a Monte Carlo Markov Chain method, we determine the equilibrium distribution of orbital inclinations in the microcanonical ensemble with fixed Etot and Ltot for isolated nuclear star clusters with a power-law distribution of a, e, and m, where m is the stellar mass. We explore the possible equilibria for nine representative Etot–Ltot pairs that cover the possible parameter space. For all cases, the equilibria show anisotropic mass segregation, where the distribution of more massive objects is more flattened than that for lighter objects. Given that stellar black holes are more massive than the average main-sequence stars, these findings suggest that black holes reside in disc-like structures within nuclear star clusters for a wide range of initial conditions. |
| first_indexed | 2024-03-07T07:41:59Z |
| format | Journal article |
| id | oxford-uuid:1cca56de-090e-4f9a-97c3-532f60d9be41 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:41:59Z |
| publishDate | 2023 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:1cca56de-090e-4f9a-97c3-532f60d9be412023-05-02T15:38:35ZBlack hole discs and spheres in galactic nuclei – exploring the landscape of vector resonant relaxation equilibriaJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1cca56de-090e-4f9a-97c3-532f60d9be41EnglishSymplectic ElementsOxford University Press2023Máthé, GSzölgyén, ÁKocsis, BVector resonant relaxation (VRR) is known to be the fastest gravitational process that shapes the geometry of stellar orbits in nuclear star clusters. This leads to the realignment of the orbital planes on the corresponding VRR time-scale tVRR of a few million years, while the eccentricity e and semimajor axis a of the individual orbits are approximately conserved. The distribution of orbital inclinations reaches an internal equilibrium characterized by two conserved quantities, the total potential energy among stellar orbits, Etot, and the total angular momentum, Ltot. On time-scales longer than tVRR, the eccentricities and semimajor axes change slowly, and the distribution of orbital inclinations are expected to evolve through a series of VRR equilibria. Using a Monte Carlo Markov Chain method, we determine the equilibrium distribution of orbital inclinations in the microcanonical ensemble with fixed Etot and Ltot for isolated nuclear star clusters with a power-law distribution of a, e, and m, where m is the stellar mass. We explore the possible equilibria for nine representative Etot–Ltot pairs that cover the possible parameter space. For all cases, the equilibria show anisotropic mass segregation, where the distribution of more massive objects is more flattened than that for lighter objects. Given that stellar black holes are more massive than the average main-sequence stars, these findings suggest that black holes reside in disc-like structures within nuclear star clusters for a wide range of initial conditions. |
| spellingShingle | Máthé, G Szölgyén, Á Kocsis, B Black hole discs and spheres in galactic nuclei – exploring the landscape of vector resonant relaxation equilibria |
| title | Black hole discs and spheres in galactic nuclei – exploring the landscape of vector resonant relaxation equilibria |
| title_full | Black hole discs and spheres in galactic nuclei – exploring the landscape of vector resonant relaxation equilibria |
| title_fullStr | Black hole discs and spheres in galactic nuclei – exploring the landscape of vector resonant relaxation equilibria |
| title_full_unstemmed | Black hole discs and spheres in galactic nuclei – exploring the landscape of vector resonant relaxation equilibria |
| title_short | Black hole discs and spheres in galactic nuclei – exploring the landscape of vector resonant relaxation equilibria |
| title_sort | black hole discs and spheres in galactic nuclei exploring the landscape of vector resonant relaxation equilibria |
| work_keys_str_mv | AT matheg blackholediscsandspheresingalacticnucleiexploringthelandscapeofvectorresonantrelaxationequilibria AT szolgyena blackholediscsandspheresingalacticnucleiexploringthelandscapeofvectorresonantrelaxationequilibria AT kocsisb blackholediscsandspheresingalacticnucleiexploringthelandscapeofvectorresonantrelaxationequilibria |