Simple distribution functions for stellar disks

Distribution functions (DFs) for dynamically warm thin stellar disks residi ng in arbitrary axisymmetric potentials are presented, which approximately reproduce predescribed surface density and velocity dispersion profiles. Th e functional form of the DFs is obtained by "warming up" a model made entir ely of circular orbits. This can be done in various ways, giving different functional forms for the DF. In the best case, the DF reproduces the predes cribed profiles to within a few percent for a typical case reminiscent of t he old stellar disk in the Milky Way. This match may be improved to about 1 % or better by a simple iterative method. An algorithm is given to draw pha se-space points randomly from the DFs for the purpose of, e.g., N-body simu lations. All the relevant computer programs are available from the author.