Relaxation of spherical stellar systems
Abstract
10,000 simulations of 1000-particle realisations of the same cluster are computed by direct force summation. Over three crossing times the original Poisson noise is amplified more than tenfold by self-gravity. The cluster's fundamental dipole mode is strongly excited by Poisson noise, and this mode makes a major contribution to driving diffusion of stars in energy. The diffusive flow through action space is computed for the simulations and compared with the predictions of both local-scattering theory and the Balescu-Lenard (BL) equation. The predictions of local-scattering theory are qualitatively wrong because the latter neglects self-gravity. These results imply that local-scattering theory is of little value. Future work on cluster evolution should employ either N-body simulation or the BL equation. However, significant code development will be required to make use of the BL equation practicable.
Cite
@article{arxiv.1906.11651,
title = {Relaxation of spherical stellar systems},
author = {Jun Yan Lau and James Binney},
journal= {arXiv preprint arXiv:1906.11651},
year = {2019}
}
Comments
Submitted to MNRAS