%0 Journal Article
%T Self-gravity, Resonances, and Orbital Diffusion in Stellar Disks
%+ Institut d'Astrophysique de Paris (IAP)
%+ Université Pierre et Marie Curie - Paris 6 (UPMC)
%A Fouvry, Jean-Baptiste
%A Binney, James
%A Pichon, Christophe
%< avec comité de lecture
%@ 0004-637X
%J The Astrophysical Journal
%I American Astronomical Society
%V 806
%8 2015
%D 2015
%Z 1504.04834
%Z 2015ApJ...806..117F
%R 10.1088/0004-637X/806/1/117
%K diffusion
%K galaxies: evolution
%K galaxies: kinematics and dynamics
%K galaxies: spiral
%K gravitation
%K Astrophysics - Astrophysics of Galaxies
%Z Sciences of the Universe [physics]Journal articles
%X Fluctuations in a stellar system's gravitational field cause the orbits of stars to evolve. The resulting evolution of the system can be computed with the orbit-averaged Fokker-Planck equation once the diffusion tensor is known. We present the formalism that enables one to compute the diffusion tensor from a given source of noise in the gravitational field when the system's dynamical response to that noise is included. In the case of a cool stellar disk we are able to reduce the computation of the diffusion tensor to a one-dimensional integral. We implement this formula for a tapered Mestel disk that is exposed to shot noise and find that we are able to explain analytically the principal features of a numerical simulation of such a disk. In particular the formation of narrow ridges of enhanced density in action space is recovered. As the disk's value of Toomre's Q is reduced and the disk becomes more responsive, there is a transition from a regime of heating in the inner regions of the disk through the inner Lindblad resonance to one of radial migration of near-circular orbits via the corotation resonance in the intermediate regions of the disk. The formalism developed here provides the ideal framework in which to study the long-term evolution of all kinds of stellar disks.
%G English
%L insu-03644938
%U https://insu.hal.science/insu-03644938
%~ INSU
%~ UPMC
%~ CNRS
%~ IAP
%~ UPMC_POLE_2
%~ SORBONNE-UNIVERSITE
%~ SU-INF-2018
%~ SU-SCIENCES
%~ SU-TI
%~ ALLIANCE-SU