N-body simulations of collisionless collapse have offered important clues to the construction of realistic stellar dynamical models of elliptical galaxies. Such simulations confirm and quantify the qualitative expectation that rapid collapse of a self-gravitating collisionless system, initially cool and significantly far from equilibrium, leads to incomplete relaxation, that is to a quasi-equilibrium configuration characterized by isotropic, quasi-Maxwellian distribution of stellar orbits in the inner regions and by radially biased anisotropic pressure in the outer parts. In earlier studies, as illustrated in a number of papers several years ago (see Bertin et al. 1993 and references therein), the attention was largely focused on the successful comparison between the models (constructed under the qualitative clues offered by the N-body simulations mentioned above) and the observations. In this paper we revisit the problem of incomplete violent relaxation, by making a direct comparison between the detailed properties of a family of distribution functions and those of the products of collisionless collapse found in N-body simulations.
Dynamical properties of a family of collisionless models of elliptical galaxies / G. Bertin, M. Trenti (AIP CONFERENCE PROCEEDINGS). - In: Plasmas in the laboratory and in the universe: New insights and new challenges / [a cura di] G. Bertin, D. Farina, R. Pozzoli. - [s.l] : American Institute of Physics, 2004 Apr. - ISBN 0735401764. - pp. 318-321 (( convegno Conference on Plasmas in the Laboratory and in the Universe : September, 16th-19th tenutosi a Como nel 2003 [10.1063/1.1718474].
Dynamical properties of a family of collisionless models of elliptical galaxies
G. BertinPrimo
;
2004
Abstract
N-body simulations of collisionless collapse have offered important clues to the construction of realistic stellar dynamical models of elliptical galaxies. Such simulations confirm and quantify the qualitative expectation that rapid collapse of a self-gravitating collisionless system, initially cool and significantly far from equilibrium, leads to incomplete relaxation, that is to a quasi-equilibrium configuration characterized by isotropic, quasi-Maxwellian distribution of stellar orbits in the inner regions and by radially biased anisotropic pressure in the outer parts. In earlier studies, as illustrated in a number of papers several years ago (see Bertin et al. 1993 and references therein), the attention was largely focused on the successful comparison between the models (constructed under the qualitative clues offered by the N-body simulations mentioned above) and the observations. In this paper we revisit the problem of incomplete violent relaxation, by making a direct comparison between the detailed properties of a family of distribution functions and those of the products of collisionless collapse found in N-body simulations.Pubblicazioni consigliate
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