Vector Resonant Relaxation of Stars around a Massive Black Hole [GA]

http://arxiv.org/abs/1812.07053


In the vicinity of a massive black hole, stars move on precessing Keplerian orbits. The mutual stochastic gravitational torques between the stellar orbits drive a rapid reorientation of their orbital planes, through a process called vector resonant relaxation. We derive, from first principles, the correlation of the potential fluctuations in such a system, and the statistical properties of random walks undergone by the stellar orbital orientations. We compare this new analytical approach with effective $N$-body simulations. We also provide a simple scheme to generate the random walk of a test star’s orbital orientation using a stochastic equation of motion. We finally present quantitative estimations of this process for a nuclear stellar cluster such as the one of the Milky Way.

Read this paper on arXiv…

J. Fouvry, B. Bar-Or and P. Chavanis
Wed, 19 Dec 18
77/84

Comments: 23 pages, 10 figures, submitted to AAS journals