Orbit-superposition models of discrete, incomplete stellar kinematics: application to the Galactic centre
We present a method for fitting orbit-superposition ("Schwarzschild") models to the kinematics of discrete stellar systems when the available stellar sample is not complete, but has been filtered by a known selection function. As an example, we apply it to Fritz et al.'s kinematics of...
| Autor principal: | |
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| Formato: | Journal article |
| Publicado em: |
Oxford University Press
2019
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| _version_ | 1826263152284663808 |
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| author | Magorrian, J |
| author_facet | Magorrian, J |
| author_sort | Magorrian, J |
| collection | OXFORD |
| description | We present a method for fitting orbit-superposition ("Schwarzschild") models to the kinematics of discrete stellar systems when the available stellar sample is not complete, but has been filtered by a known selection function. As an example, we apply it to Fritz et al.'s kinematics of the innermost regions of the Milky Way's nuclear stellar cluster. Assuming spherical symmetry, our models fit a black hole of mass $M_\bullet=(3.76\pm0.22)\times10^6\,M_\odot$, surrounded by an extended mass $M_\star=(6.57\pm0.54)\times10^6\,M_\odot$ within 4 parsec. The best-fitting mass models have an approximate power-law density cusp $\rho\propto r^{-\gamma}$ within 1 parsec, with $\gamma=1.3\pm0.3$. We carry out an extensive investigation of how our modelling assumptions might bias these estimates: $M_\bullet$ is the most robust parameter and $\gamma$ the least. Internally the best-fitting models have broadly isotropic orbit distributions, apart from a bias towards circular orbits between 0.1 and 0.3 parsec. |
| first_indexed | 2024-03-06T19:47:09Z |
| format | Journal article |
| id | oxford-uuid:22b3a4fe-3699-4895-a962-c5510b94f5a3 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T19:47:09Z |
| publishDate | 2019 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:22b3a4fe-3699-4895-a962-c5510b94f5a32022-03-26T11:40:12ZOrbit-superposition models of discrete, incomplete stellar kinematics: application to the Galactic centreJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:22b3a4fe-3699-4895-a962-c5510b94f5a3Symplectic Elements at OxfordOxford University Press2019Magorrian, JWe present a method for fitting orbit-superposition ("Schwarzschild") models to the kinematics of discrete stellar systems when the available stellar sample is not complete, but has been filtered by a known selection function. As an example, we apply it to Fritz et al.'s kinematics of the innermost regions of the Milky Way's nuclear stellar cluster. Assuming spherical symmetry, our models fit a black hole of mass $M_\bullet=(3.76\pm0.22)\times10^6\,M_\odot$, surrounded by an extended mass $M_\star=(6.57\pm0.54)\times10^6\,M_\odot$ within 4 parsec. The best-fitting mass models have an approximate power-law density cusp $\rho\propto r^{-\gamma}$ within 1 parsec, with $\gamma=1.3\pm0.3$. We carry out an extensive investigation of how our modelling assumptions might bias these estimates: $M_\bullet$ is the most robust parameter and $\gamma$ the least. Internally the best-fitting models have broadly isotropic orbit distributions, apart from a bias towards circular orbits between 0.1 and 0.3 parsec. |
| spellingShingle | Magorrian, J Orbit-superposition models of discrete, incomplete stellar kinematics: application to the Galactic centre |
| title | Orbit-superposition models of discrete, incomplete stellar kinematics: application to the Galactic centre |
| title_full | Orbit-superposition models of discrete, incomplete stellar kinematics: application to the Galactic centre |
| title_fullStr | Orbit-superposition models of discrete, incomplete stellar kinematics: application to the Galactic centre |
| title_full_unstemmed | Orbit-superposition models of discrete, incomplete stellar kinematics: application to the Galactic centre |
| title_short | Orbit-superposition models of discrete, incomplete stellar kinematics: application to the Galactic centre |
| title_sort | orbit superposition models of discrete incomplete stellar kinematics application to the galactic centre |
| work_keys_str_mv | AT magorrianj orbitsuperpositionmodelsofdiscreteincompletestellarkinematicsapplicationtothegalacticcentre |