Open AccessFlattened Jaffe models for galaxies
Author(s) -
Zhenglu Jiang
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.1365-8711.2000.03900.x
Subject(s) - physics , galaxy , anisotropy , mass distribution , distribution (mathematics) , rotational symmetry , distribution function , oblate spheroid , stars , astrophysics , classical mechanics , statistical physics , mathematical analysis , quantum mechanics , mechanics , mathematics
This paper introduces a class of galactic models which extend Jaffe's spherical models to axisymmetric systems, and then studies the properties of their densities and two‐integral even distribution functions. The models have finite total mass and finite densities which, at large distances, decay radially like r −4 except on the major axis, and like r −3 on the major axis. The more flattened the galaxy, the stronger is the dependence of the even distribution functions on the angular momenta of its stars. Their distribution functions can be obtained by using the maximum entropy principle or assuming the anisotropy of the models. In particular, some formulae analogous to those of Hunter & Qian are obtained to calculate two‐integral odd distribution functions, and they can be applied to obtain the distribution functions under the assumption of anisotropy for the oblate models.