1996/01/10 by Walter Dehnen, Dehnen, Walter, James Binney +1
Physics and Astronomy · #Astro and Planetary Science #Astrophysics (astro-ph) #FOS: Physical sciences #Scientific Research and Discoveries #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9601040
10 pages, LaTeX, style file and 4 figures included. Invited talk presented at the meeting ``Formation of the Galactic Halo ... Inside and Out'', Tucson, October 9-11. Full .ps file available at ftp://ftp.physics.ox.ac.uk/pub/local/users/dehnen/MilkyWayModels.ps.gz
arxiv created 1996/01/10 · openalex publication_date 1996/01/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The only way to map the Galaxy's gravitational potential Φ(\bf x) and the distribution of matter that produces it is by modelling the dynamics of stars and gas. Observations of the kinematics of gas provide key information about gradients of Φ within the plane, but little information about the structure of Φ out of the plane. Traditional Galaxy models \em assume, for each of the Galaxy's components, arbitrary flattenings, which together with the components' relative masses yield the model's equipotentials. However, the Galaxy's isopotential surfaces should be \em determined\/ directly from the motions of stars that move far from the plane. Moreover, from the kinematics of samples of such stars that have well defined selection criteria, one should be able not only to map Φ at all positions, but to determine the distribution function fi(\bf x,\bf v) of each stellar population i studied. These distribution functions will contain a wealth of information relevant to the formation and evolution of the Galaxy. An approach to fitting a wide class of dynamical models to the very heterogeneous body of available data is described and illustrated.