{
  "id": "2107.02802",
  "version": "v1",
  "published": "2021-07-06T18:00:00.000Z",
  "updated": "2021-07-06T18:00:00.000Z",
  "title": "Evidence for low kick velocities among high-mass X-ray binaries in the Small Magellanic Cloud from the spatial correlation function",
  "authors": [
    "A. Bodaghee",
    "V. Antoniou",
    "A. Zezas",
    "J. A. Tomsick",
    "Z. Jordan",
    "E. Frechette",
    "B. Jackson",
    "R. Agnew",
    "A. E. Hornschemeier",
    "J. Rodriguez"
  ],
  "comment": "10 pages, 7 figures, accepted for publication in the Astrophysical Journal",
  "categories": [
    "astro-ph.HE",
    "astro-ph.GA"
  ],
  "abstract": "We present the two-point cross-correlation function between high-mass X-ray binaries (HMXBs) in the Small Magellanic Cloud (SMC) and their likely birthplaces (OB Associations: OBAs). This function compares the spatial correlation between the observed HMXB and OBA populations against mock catalogs in which the members are distributed randomly across the sky. A significant correlation (15 sigma) is found for the HMXB and OBA populations when compared with a randomized catalog in which the OBAs are distributed uniformly over the SMC. A less significant correlation (4 sigma) is found for a randomized catalog of OBAs built with a bootstrap method. However, no significant correlation is detected when the randomized catalogs assume the form of a Gaussian ellipsoid or a distribution that reflects the star-formation history from 40 Myr ago. Based on their observed distributions and assuming a range of migration timescales, we infer that the average value of the kick velocity inherited by an HMXB during the formation of its compact object is 2-34 km/s. This is considerably less than the value obtained for their counterparts in the Milky Way hinting that the galactic environment affecting stellar evolution plays a role in setting the average kick velocity of HMXBs.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-07-06T18:00:00.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high-mass x-ray binaries",
      "small magellanic cloud",
      "kick velocity",
      "low kick velocities",
      "spatial correlation function"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}