Some formulae are presented for finding two-integral distribution functions
(DFs) which depends only on the two classical integrals of the energy and the
magnitude of the angular momentum with respect to the axis of symmetry for
stellar systems with known axisymmetric densities. They come from an
combination of the ideas of
Eddington and Fricke and they are also an extension of those shown by Jiang
and Ossipkov for finding anisotropic DFs for spherical galaxies. The density of
the system is required to be expressed as a sum of products of functions of the
potential and of the radial coordinate. The solution corresponding to this type
of density is in turn a sum of products of functions of the energy and of the
magnitude of the angular momentum about the axis of symmetry. The product of
the density and its radial velocity dispersion can be also expressed as a sum
of products of functions of the potential and of the radial coordinate. It can
be further known that the density multipied by its rotational velocity
dispersion is equal to a sum of products of functions of the potential and of
the radial coordinate minus the product of the density and the square of its
mean rotational velocity. These formulae can be applied to the Binney and the
Lynden-Bell models. An infinity of the odd DFs for the Binney model can be also
found under the assumption of the laws of the rotational velocity
Abstract.Metallicities and distances have been determined from Vilnius photometry for an in situ sample of nearly 650 stars in eight proper-motion fields at high Galactic latitudes. For half of these stars, radial velocities have been measured with the CORAVEL spectrometer, which allowed us to derive spatial velocities and Galactic orbits. In this contribution we present a status report on our results for the stellar content of the Galactic disk, with emphasis given to specific aspects of distinguishing the thick-disk stars from the old thin-disk population.
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A method is presented for finding anisotropic distribution functions for
stellar systems with known, spherically symmetric, densities, which depends
only on the two classical integrals of the energy and the magnitude of the
angular momentum. It requires the density to be expressed as a sum of products
of functions of the potential and of the radial coordinate. The solution
corresponding to this type of density is in turn a sum of products of functions
of the energy and of the magnitude of the angular momentum. The products of the
density and its radial and transverse velocity dispersions can be also
expressed as a sum of products of functions of the potential and of the radial
coordinate. Several examples are given, including some of new anisotropic
distribution functions. This device can be extended further to the related
problem of finding two-integral distribution functions for axisymmetric
galaxies.Comment: 5 figure
Using the equipotential method we introduce a class of flattened γ models for galaxies and study the properties of their potential-density pairs and two-integral distribution functions.
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