Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453
Most stellar-dynamical determinations of the masses of nearby supermassive black holes (SMBHs) have been obtained with the orbit superposition technique under the assumption of axisymmetry. However, few galaxies—in particular massive early-type galaxies—obey exact axisymmetry. Here we present a revi...
| Principais autores: | , , |
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| Formato: | Artigo |
| Idioma: | English |
| Publicado em: |
IOP Publishing
2022-01-01
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| coleção: | The Astrophysical Journal |
| Assuntos: | |
| Acesso em linha: | https://doi.org/10.3847/1538-4357/ac3e68 |
| _version_ | 1827387237147344896 |
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| author | Matthew E. Quenneville Emily R. Liepold Chung-Pei Ma |
| author_facet | Matthew E. Quenneville Emily R. Liepold Chung-Pei Ma |
| author_sort | Matthew E. Quenneville |
| collection | DOAJ |
| description | Most stellar-dynamical determinations of the masses of nearby supermassive black holes (SMBHs) have been obtained with the orbit superposition technique under the assumption of axisymmetry. However, few galaxies—in particular massive early-type galaxies—obey exact axisymmetry. Here we present a revised orbit superposition code and a new approach for dynamically determining the intrinsic shapes and mass parameters of triaxial galaxies based on spatially resolved stellar kinematic data. The triaxial TriOS code described here corrects an error in the original van den Bosch et al. code that gives rise to incorrect projections for most orbits in triaxial models and can significantly impact parameter search results. The revised code also contains significant improvements in orbit sampling, mass constraints, and run time. Furthermore, we introduce two new parameter-searching strategies—a new set of triaxial shape parameters and a novel grid-free sampling technique—that together lead to a remarkable gain in efficiency in locating the best-fit model. We apply the updated code and search method to NGC 1453, a fast-rotating massive elliptical galaxy. A full 6D parameter search finds $p=b/a={0.933}_{-0.015}^{+0.014}$ and q = c / a = 0.779 ± 0.012 for the intrinsic axis ratios and T = 0.33 ± 0.06 for the triaxiality parameter. Despite the deviations from axisymmetry, the best-fit SMBH mass, stellar mass-to-light ratio, and dark matter enclosed mass for NGC 1453 are consistent with the axisymmetric results. More comparisons between axisymmetric and triaxial modeling are needed before drawing general conclusions. |
| first_indexed | 2024-03-08T15:59:02Z |
| format | Article |
| id | doaj.art-ee143c7ac8a74ca79456402fdfab43a8 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T15:59:02Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-ee143c7ac8a74ca79456402fdfab43a82024-01-08T14:40:33ZengIOP PublishingThe Astrophysical Journal1538-43572022-01-0192613010.3847/1538-4357/ac3e68Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453Matthew E. Quenneville0https://orcid.org/0000-0002-6148-5481Emily R. Liepold1https://orcid.org/0000-0002-7703-7077Chung-Pei Ma2https://orcid.org/0000-0002-4430-102XDepartment of Astronomy, University of California , Berkeley, CA 94720, USA ; mquenneville@berkeley.edu; Department of Physics, University of California , Berkeley, CA 94720, USADepartment of Astronomy, University of California , Berkeley, CA 94720, USA ; mquenneville@berkeley.edu; Department of Physics, University of California , Berkeley, CA 94720, USADepartment of Astronomy, University of California , Berkeley, CA 94720, USA ; mquenneville@berkeley.edu; Department of Physics, University of California , Berkeley, CA 94720, USAMost stellar-dynamical determinations of the masses of nearby supermassive black holes (SMBHs) have been obtained with the orbit superposition technique under the assumption of axisymmetry. However, few galaxies—in particular massive early-type galaxies—obey exact axisymmetry. Here we present a revised orbit superposition code and a new approach for dynamically determining the intrinsic shapes and mass parameters of triaxial galaxies based on spatially resolved stellar kinematic data. The triaxial TriOS code described here corrects an error in the original van den Bosch et al. code that gives rise to incorrect projections for most orbits in triaxial models and can significantly impact parameter search results. The revised code also contains significant improvements in orbit sampling, mass constraints, and run time. Furthermore, we introduce two new parameter-searching strategies—a new set of triaxial shape parameters and a novel grid-free sampling technique—that together lead to a remarkable gain in efficiency in locating the best-fit model. We apply the updated code and search method to NGC 1453, a fast-rotating massive elliptical galaxy. A full 6D parameter search finds $p=b/a={0.933}_{-0.015}^{+0.014}$ and q = c / a = 0.779 ± 0.012 for the intrinsic axis ratios and T = 0.33 ± 0.06 for the triaxiality parameter. Despite the deviations from axisymmetry, the best-fit SMBH mass, stellar mass-to-light ratio, and dark matter enclosed mass for NGC 1453 are consistent with the axisymmetric results. More comparisons between axisymmetric and triaxial modeling are needed before drawing general conclusions.https://doi.org/10.3847/1538-4357/ac3e68Elliptical galaxiesGalaxiesGiant elliptical galaxiesGalaxy dynamicsGalaxy kinematicsGalaxy structure |
| spellingShingle | Matthew E. Quenneville Emily R. Liepold Chung-Pei Ma Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453 The Astrophysical Journal Elliptical galaxies Galaxies Giant elliptical galaxies Galaxy dynamics Galaxy kinematics Galaxy structure |
| title | Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453 |
| title_full | Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453 |
| title_fullStr | Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453 |
| title_full_unstemmed | Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453 |
| title_short | Triaxial Orbit-based Dynamical Modeling of Galaxies with Supermassive Black Holes and an Application to Massive Elliptical Galaxy NGC 1453 |
| title_sort | triaxial orbit based dynamical modeling of galaxies with supermassive black holes and an application to massive elliptical galaxy ngc 1453 |
| topic | Elliptical galaxies Galaxies Giant elliptical galaxies Galaxy dynamics Galaxy kinematics Galaxy structure |
| url | https://doi.org/10.3847/1538-4357/ac3e68 |
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