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 30pc≲R≲300pc⁠. We construct axisymmetric self-consistent equilibrium dynamical models of the NSD in which the distribution function is an anal...

Descripción completa

Detalles Bibliográficos
Autores: Sormani, Mattia C., Sanders, Jason L., Fritz, Tobias K., Smith, Leigh C., Gerhard, Ortwin, Schödel, Rainer, Magorrian, John, Neumayer, Nadine, Nogueras-Lara, Francisco, Feldmeier-Krause, Anja, Mastrobuono-Battisti, Alessandra, Schultheis, Mathias, Shahzamanian, B., Vasiliev, Eugene, Klessen, Ralf S., Lucas, Philip, Minniti, Dante
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:dnet:digitalcsic_::7b68991b3fab56e2e2bb10855cd0a7c7
Acceso en línea:http://hdl.handle.net/10261/274908
Access Level:acceso abierto
Palabra clave:Galaxy: centre
Galaxy: kinematics and dynamics
Galaxy: structure
Descripción
Sumario:The nuclear stellar disc (NSD) is a flattened high-density stellar structure that dominates the gravitational field of the Milky Way at Galactocentric radius 30pc≲R≲300pc⁠. 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 MNSD=10.5+1.1−1.0×108M⊙⁠, roughly exponential radial and vertical scale lengths of Rdisc=88.6+9.2−6.9pc and Hdisc=28.4+5.5−5.5pc⁠, respectively, and a velocity dispersion σ≃70kms−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. © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.

Similares en LA Referencia