{
  "id": "1705.07669",
  "version": "v1",
  "published": "2017-05-22T11:22:34.000Z",
  "updated": "2017-05-22T11:22:34.000Z",
  "title": "The Spin Distribution of Fast Spinning Neutron Stars in Low Mass X-Ray Binaries: Evidence for Two Sub-Populations",
  "authors": [
    "A. Patruno",
    "B. Haskell",
    "N. Andersson"
  ],
  "comment": "Submitted to ApJ",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We study the current sample of rapidly rotating neutron stars in both accreting and non-accreting binaries in order to determine whether the spin distribution of accreting neutron stars in low-mass X-ray binaries can be reconciled with current accretion torque models. We perform a statistical analysis of the spin distributions and show that there is evidence for two sub-populations among low-mass X-ray binaries, one at relatively low spin frequency, with an average of ~300 Hz and a broad spread, and a peaked population at higher frequency with average spin frequency of ~575 Hz. We show that the two sub-populations are separated by a cut-point at a frequency of ~540 Hz. We also show that the spin frequency of radio millisecond pulsars does not follow a log-normal distribution and shows no evidence for the existence of distinct sub-populations. We discuss the uncertainties of different accretion models and speculate that either the accreting neutron star cut-point marks the onset of gravitational waves as an efficient mechanism to remove angular momentum or some of the neutron stars in the fast sub-population do not evolve into radio millisecond pulsars.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-05-22T11:22:34.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "low mass x-ray binaries",
      "fast spinning neutron stars",
      "spin distribution",
      "neutron star cut-point marks",
      "sub-population"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}