A new dynamically self-consistent version of the Besançon Galaxy model
1
Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, 11 rue de l’Université, 67000
Strasbourg, France
e-mail: olivier.bienayme@unistra.fr
2
Université de Franche-Comté, OSU THETA Franche-Comté-Bourgogne, Observatoire de Besançon, Institut Utinam, CNRS UMR 6213, BP 1615, 25010
Besançon Cedex, France
Received:
8
May
2018
Accepted:
10
July
2018
Context. Dynamically self-consistent galactic models are necessary for analysing and interpreting star counts, stellar density distributions, and stellar kinematics in order to understand the formation and the evolution of our Galaxy.
Aims. We modify and improve the dynamical self-consistency of the Besançon Galaxy model in the case of a stationary and axisymmetric gravitational potential.
Methods. Each stellar orbit is modelled by determining a Stäckel approximate integral of motion. Generalised Shu distribution functions (DFs) with three integrals of motion are used to model the stellar distribution functions.
Results. This new version of the Besançon model is compared with the previous axisymmetric BGM2014 version and we find that the two versions have similar densities for each stellar component. The dynamically self-consistency is improved and can be tested by recovering the forces and the potential through the Jeans equations applied to each stellar distribution function. Forces are recovered with an accuracy better than one per cent over most of the volume of the Galaxy.
Key words: Galaxy: kinematics and dynamics / methods: numerical
© ESO 2018
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.