English

Origin of the Break and Mass-Dependence in the Wide-Binary Projected-Separation Distribution

Astrophysics 2007-05-23 v2

Abstract

The distribution of Galactic-disk wide binaries shows a clear break in slope at projected separations of about r_\perp ~ 2500 AU in two basically independent surveys by Chaname & Gould and Lepine & Bongiorno. The latter also showed that the frequency of wide-binary companions to G-star primaries declines monotonically as a function of companion mass. We show that both effects can be explained by the operation of Heggie's law in the typical open-cluster environments where binaries form. One immediate conclusion is that most Galactic-disk stars formed in open clusters with internal dispersions of a few hundred meters per second and disruption times of a few hundred million years.

Keywords

Cite

@article{arxiv.astro-ph/0610799,
  title  = {Origin of the Break and Mass-Dependence in the Wide-Binary Projected-Separation Distribution},
  author = {Andrew Gould and Jason Eastman},
  journal= {arXiv preprint arXiv:astro-ph/0610799},
  year   = {2007}
}

Comments

submitted to ApJ Letters, 4 pages + 1 figure