Lowered Nonextensive Stellar Distribution

Abstract

The structure of globular clusters and elliptical galaxies are described in an unified way through a new class of lowered models inspired on the nonextensive kinetic theory. These power law models are specified by a single parameter q which quantifies to what extent they depart from the class of lowered stellar distributions discussed by Michie and King. For q equal to unity, the Michie-King profiles are recovered. However, for q smaller than unity there is a gradual modification in the shape of the density profiles which depends on the degree of tidal damage imposed on the model, thereby also providing a good fit for globular clusters. It is also shown that a subclass of these models, those with a deeper potential and $q$ slightly less than unity, present a distribution resembling the de Vaucoulers $r^{1/4}$ profile which yields a good description of the structure of elliptical galaxies. This subset of models follows this trend, with a slight departure over nearly 10 orders of magnitudes.