English

Exponential Disks from Stellar Scattering: III. Stochastic Models

Astrophysics of Galaxies 2016-10-26 v1

Abstract

Stellar scattering off irregularities in a galaxy disk has been shown to make an exponential radial profile, but no fundamental reason for this has been suggested. Here we show that exponentials are mathematically expected from random scattering in a disk when there is a slight inward bias in the scattering probability. Such a bias was present in our previous scattering experiments that formed exponential profiles. Double exponentials can arise when the bias varies with radius. This is a fundamental property of scattering and may explain why piece-wise exponential profiles are ubiquitous in galaxies, even after minor mergers and other disruptive events.

Keywords

Cite

@article{arxiv.1607.07595,
  title  = {Exponential Disks from Stellar Scattering: III. Stochastic Models},
  author = {Bruce G. Elmegreen and Curtis Struck},
  journal= {arXiv preprint arXiv:1607.07595},
  year   = {2016}
}

Comments

15 pages, 6 figures, accepted for Astrophysical Journal

R2 v1 2026-06-22T15:04:15.204Z