تقرير
Self-consistent modelling of the Milky Way's Nuclear Stellar Disc
| العنوان: | Self-consistent modelling of the Milky Way's Nuclear Stellar Disc |
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| المؤلفون: | Sormani, Mattia C., Sanders, Jason L., Fritz, Tobias K., Smith, Leigh C., Gerhard, Ortwin, Schoedel, Rainer, Magorrian, John, Neumayer, Nadine, Nogueras-Lara, Francisco, Feldmeier-Krause, Anja, Mastrobuono-Battisti, Alessandra, Schultheis, Mathias, Shahzamanian, Banafsheh, Vasiliev, Eugene, Klessen, Ralf S., Lucas, Philip, Minniti, Dante |
| سنة النشر: | 2021 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | The Nuclear Stellar Disc (NSD) is a flattened high-density stellar structure that dominates the gravitational field of the Milky Way at Galactocentric radius $30\lesssim R\lesssim 300$ 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 normalised 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 marginalised probability distributions give a total mass of $M_{\rm NSD} = 10.5^{+1.1}_{-1.0} \times10^8 \,{\rm M_\odot}$, roughly exponential radial and vertical scale-lengths of $R_{\rm disc} = 88.6^{+9.2}_{-6.9}$ pc and $H_{\rm disc}=28.4^{+5.5}_{-5.5}$ pc respectively, and a velocity dispersion $\sigma \simeq 70$ km/s 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. Comment: Accepted for publication in MNRAS |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/stac639 |
| URL الوصول: | http://arxiv.org/abs/2111.12713 |
| رقم الأكسشن: | edsarx.2111.12713 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/mnras/stac639 |
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