Dark Matter Halos: The Dynamical Basis of Effective Empirical Models. (14th September 2010)

• Record Type: Journal Article
• Authors: Lapi, Andrea; Cavaliere, Alfonso
• Other Names: Castro-Tirado Alberto J. Academic Editor.
• Is Part Of: Advances in astronomy. Volume 2011(2011)
• Publication Date: 2010-09-14
• Subjects: Astronomy -- Periodicals; Astronomy; Periodicals; 520
• DOI: 10.1155/2011/903429
• Languages: English
• ISSNs: 1687-7977

Abstract

Abstract : We investigate the dynamical basis of the classic empirical models (specifically, Sérsic-Einasto and generalized NFW) that are widely used to describe the distributions of collisionless matter in galaxies. We submit that such a basis is provided by ourα -profiles, shown to constitute solutions of the Jeans dynamical equilibrium with physical boundary conditions. We show how to set the parameters of the empirical in terms of the dynamical models; we find the empirical models, and specifically Sérsic-Einasto, to constitute a simple and close approximation to the dynamical models. Finally, we discuss how these provide a useful baseline for assessing the impact of the small-scale dynamics that may modulate the density slope in the central galaxy regions.