{
  "id": "1310.0417",
  "version": "v1",
  "published": "2013-10-01T18:22:27.000Z",
  "updated": "2013-10-01T18:22:27.000Z",
  "title": "SWIFT J1910.2-0546: A possible black hole binary with a retrograde spin or truncated disk",
  "authors": [
    "R. C. Reis",
    "M. T. Reynolds",
    "J. M. . Miller",
    "D. J. Walton",
    "D. Maitra",
    "A. King",
    "N. Degenaar"
  ],
  "comment": "Accepted for publication in The Astrophysical Journal. 11 pages, 11 figures and 1 Table",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present the first results from a long (51 ks) XMM-Newton observation of the Galactic X-ray binary Swift J1910.2-0546 in a intermediate state, obtained during its 2012 outburst. A clear, asymmetric iron emission line is observed and physically motivated models are used to fully describe the emission-line profile. Unlike other sources in their intermediate spectral states, the inner accretion disk in Swift J1910.2-0546 appears to be truncated, with an inner radius of \\rin$=9.4^{+1.7}_{-1.3}$\\rg\\ at a 90% confidence limit. Quasi-periodic oscillations are also found at approximately 4.5 and 6 hz, which correlates well with the break frequency of the underlying broad-band noise. Assuming that the line emission traces the ISCO, as would generally be expected for an intermediate state, the current observation of Swift J1910.2-0546 may offer the best evidence for a possible retrograde stellar mass black hole with a spin parameter $a< -0.32 cJ/GM^2$ (90% confidence). Although this is an intriguing possibility, there are also a number of alternative scenarios which do not require a retrograde spin. For example, the inner accretion disk may be truncated at an unusually high luminosity in this case, potentially suffering frequent evaporation/condensation, or it could instead be persistently evacuated through mass loss in a relativistic jet. Further observations are required to distinguish between these different interpretations.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2013-10-01T18:22:27.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "black hole binary",
      "retrograde spin",
      "truncated disk",
      "inner accretion disk",
      "galactic x-ray binary swift j1910"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/778/2/155",
      "journal": "The Astrophysical Journal",
      "year": 2013,
      "month": "Dec",
      "volume": 778,
      "number": 2,
      "pages": 155
    },
    "note": {
      "typesetting": "TeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1256300,
      "adsabs": "2013ApJ...778..155R"
    }
  }
}