A new model for spherical galaxies and its distribution functions

ABSTRACT A new potential is presented for spherical galaxies. The technique of the construction of our model is similar to that given by An and Evans. In a special case, its mass density becomes a special one of the Hernquist model. Another special model is primarily discussed, and its intrinsic properties, such as velocity dispersions and surface densities, can be shown directly by numerical calculation. Its distribution functions in both isotropic and anisotropic cases can be expressed as some definite integrals which are suitable for numerical calculation.