{
  "id": "1304.5965",
  "version": "v1",
  "published": "2013-04-22T14:38:16.000Z",
  "updated": "2013-04-22T14:38:16.000Z",
  "title": "Footprints in the wind of Vela X-1 traced with MAXI",
  "authors": [
    "V. Doroshenko",
    "A. Santangelo",
    "S. Nakahira",
    "T. Mihara",
    "M. Sugizaki",
    "M. Matsuoka",
    "M. Nakajima",
    "K. Makishima"
  ],
  "comment": "5 pages, 3 figures, accepted in A&A",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "The stellar wind around the compact object in luminous wind-accreting high mass X-ray binaries is expected to be strongly ionized with the X-rays coming from the compact object. The stellar wind of hot stars is mostly driven by light absorption in lines of heavier elements, and X-ray photo-ionization significantly reduces the radiative force within the so-called Stroemgren region leading to wind stagnation around the compact object. In close binaries like Vela X-1 this effect might alter the wind structure throughout the system. Using the spectral data from Monitor of All-sky X-ray Image (MAXI), we study the observed dependence of the photoelectric absorption as function of orbital phase in Vela X-1, and find that it is inconsistent with expectations for a spherically-symmetric smooth wind. Taking into account previous investigations we develop a simple model for wind structure with a stream-like photoionization wake region of slower and denser wind trailing the neutron star responsible for the observed absorption curve.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2013-04-22T14:38:16.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "compact object",
      "wind-accreting high mass x-ray binaries",
      "wind structure",
      "stellar wind",
      "footprints"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1051/0004-6361/201321305",
      "journal": "Astronomy and Astrophysics",
      "year": 2013,
      "month": "Jun",
      "volume": 554
    },
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1229295,
      "adsabs": "2013A&A...554A..37D"
    }
  }
}