Self-consistent modelling of the Milky Way’s nuclear stellar disc
The nuclear stellar disc (NSD) is a flattened high-density stellar structure that dominates the gravitational field of the Milky Way at Galactocentric radius $30\, {\rm pc}\lesssim R\lesssim 300\, {\rm pc}$. We construct axisymmetric self-consistent equilibrium dynamical models of the NSD in which t...
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| Hauptverfasser: | , , , , , , , , , , , , , , , , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
2022 March 22
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| In: |
Monthly notices of the Royal Astronomical Society
Year: 2022, Jahrgang: 512, Heft: 2, Pages: 1857-1884 |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stac639 |
| Online-Zugang: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1093/mnras/stac639
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| Verfasserangaben: | Mattia C. Sormani, Jason L. Sanders, Tobias K. Fritz, Leigh C. Smith, Ortwin Gerhard, Rainer Schödel, John Magorrian, Nadine Neumayer, Francisco Nogueras-Lara, Anja Feldmeier-Krause, Alessandra Mastrobuono-Battisti, Mathias Schultheis, Banafsheh Shahzamanian, Eugene Vasiliev, Ralf S. Klessen, Philip Lucas and Dante Minniti |
| Zusammenfassung: | The nuclear stellar disc (NSD) is a flattened high-density stellar structure that dominates the gravitational field of the Milky Way at Galactocentric radius $30\, {\rm pc}\lesssim R\lesssim 300\, {\rm pc}$. We construct axisymmetric self-consistent equilibrium dynamical models of the NSD in which the distribution function is an analytic function of the action variables. We fit the models to the normalized kinematic distributions (line-of-sight velocities + VIRAC2 proper motions) of stars in the NSD survey of Fritz et al., taking the foreground contamination due to the Galactic Bar explicitly into account using an N-body model. The posterior marginalized probability distributions give a total mass of $M_{\rm NSD} = 10.5^{+1.1}_{-1.0} \times 10^8 \, \, \rm M_\odot$, roughly exponential radial and vertical scale lengths of $R_{\rm disc} = 88.6^{+9.2}_{-6.9} \, {\rm pc}$ and $H_{\rm disc}=28.4^{+5.5}_{-5.5} \, {\rm pc}$, respectively, and a velocity dispersion $\sigma \simeq 70\, {\rm km\, s^{-1}}$ that decreases with radius. We find that the assumption that the NSD is axisymmetric provides a good representation of the data. We quantify contamination from the Galactic Bar in the sample, which is substantial in most observed fields. Our models provide the full 6D (position + velocity) distribution function of the NSD, which can be used to generate predictions for future surveys. We make the models publicly available as part of the software package agama. |
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| Beschreibung: | Gesehen am 22.04.2022 |
| Beschreibung: | Online Resource |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stac639 |