To a large extent, the basic mechanism of dynamical friction remains an open problem. In fact, the classical idealized local description, given by Chandrasekhar, is known to be subject to a number of limitations, possibly related to the global nature of the collective processes that are involved. Here we present a study of the properties of dynamical friction in galaxy models, derived from a realistic distribution function, that are characterized by significant density concentration and by pressure anisotropy biased in the radial direction. The problem is addressed by means of dedicated N-body simulations. By following the fall of heavy objects inside the host galaxy, we find that the classical theory is better suited to describe dynamical friction only outside cores of models with low concentration, but fails in more concentrated models, more appropriate to describe elliptical galaxies. In turn, pressure anisotropy in the host galaxy does not appear to have significant effects.
Non Locality of Collective Effects Related to Dynamical Friction in Elliptical Galaxies / S.E. Arena, G. Bertin - In: Collective phenomena in macroscopic systems / [a cura di] G. Bertin, R. Pozzoli, M. Romé, K.R. Sreenivasan. - [s.l] : World Scientific Publishing Co. Pte. Ltd., 2007 Aug. - ISBN 9789812778901. - pp. 207-212 (( convegno Proceedings of the Workshop : Villa Olmo, 4 – 6 December tenutosi a Como nel 2006.
|Titolo:||Non Locality of Collective Effects Related to Dynamical Friction in Elliptical Galaxies|
ARENA, SERENA EMILY (Primo)
BERTIN, GIUSEPPE (Ultimo)
|Parole Chiave:||dynamical friction; elliptical galaxies; N–body simulations|
|Settore Scientifico Disciplinare:||Settore FIS/05 - Astronomia e Astrofisica|
|Data di pubblicazione:||ago-2007|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1142/9789812778901_0021|
|Tipologia:||Book Part (author)|
|Appare nelle tipologie:||03 - Contributo in volume|