English

Low-mass X-ray binaries ejected from globular clusters

High Energy Astrophysical Phenomena 2018-02-15 v1

Abstract

We explore the population of mass-transferring binaries ejected from globular clusters (GCs) with both black hole (BH) and neutron star (NS) accretors. We use a set of 137 fully evolved globular cluster models which span a large range in cluster properties and, overall, match very well the properties of old GCs observed in the Milky Way. We identify all binaries ejected from our set of models that eventually undergo mass-transfer. These binaries are ejected from their host clusters over a wide range of ejection times and include white dwarf, giant, and main sequence donors. We calculate the orbits of these ejected systems in the Galactic potential to determine their present-day positions in the Galaxy and compare to the distribution of observed low-mass X-ray binaries (XRBs) in the Milky Way. We estimate 300\sim 300 mass-transferring NS binaries and 180\sim 180 mass-transferring BH binaries may currently be present in the Milky Way that originated from within GCs. Of these, we estimate, based on mass-transfer rates and duty cycles at the present time, at most a few would be observable as BH--XRBs and NS--XRBs at the present day. Based on our results, XRBs that originated from GCs are unlikely to contribute significantly to the total population of low-mass XRBs in the Galactic field.

Keywords

Cite

@article{arxiv.1802.04895,
  title  = {Low-mass X-ray binaries ejected from globular clusters},
  author = {Kyle Kremer and Sourav Chatterjee and Carl L. Rodriguez and Frederic A. Rasio},
  journal= {arXiv preprint arXiv:1802.04895},
  year   = {2018}
}

Comments

Submitted to ApJ. Comments welcome

R2 v1 2026-06-23T00:21:42.984Z