Open AccessFrom kinematics to dynamics in thin galactic discs
Author(s) -
Mathieu A.,
Merrifield M. R.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03646.x
Subject(s) - physics , gravitational potential , kinematics , observable , galaxy , astrophysics , stars , gravitation , stellar dynamics , distribution function , line of sight , rotational symmetry , classical mechanics , mechanics , quantum mechanics
We present a method for recovering the distribution functions of edge‐on thin axisymmetric discs directly from their observable kinematic properties. The most generally observable properties of such a stellar system are the line‐of‐sight velocity distributions of the stars at different projected radii along the galaxy. If the gravitational potential is known, then the general two‐integral distribution function can be reconstructed using the shapes of the high‐velocity tails of these line‐of‐sight distributions. If the wrong gravitational potential is adopted, then a distribution function can still be constructed using this technique, but the low‐velocity parts of the observed velocity distributions will not be reproduced by the derived dynamical model. Thus, the gravitational potential is also tightly constrained by the observed kinematics.