{
  "id": "1910.11979",
  "version": "v1",
  "published": "2019-10-26T02:28:06.000Z",
  "updated": "2019-10-26T02:28:06.000Z",
  "title": "The spin of the black hole GRS 1716-249 determined from the hard intermediate state",
  "authors": [
    "Lian Tao",
    "John A. Tomsick",
    "Jinlu Qu",
    "Shu Zhang",
    "Shuangnan Zhang",
    "Qingcui Bu"
  ],
  "comment": "6 pages, 4 figures, 2 tables, accepted by ApJ",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present three simultaneous/quasi-simultaneous NuSTAR and Swift datasets of the black hole GRS 1716-249 in its hard intermediate state. The accretion disk in this state may have reached the innermost stable circular orbit, and the NuSTAR spectra show a broad relativistic iron line and a strong Compton hump. To measure the black hole spin, we construct a joint model consisting of a relativistic disk model kerrbb and a reflection model relxill, to fit the continuum and the reflection components, respectively. By applying this model to each dataset independently, a consistent result is obtained on the black hole spin and the disk inclination. The black hole spin is a* >~ 0.92, and the inclination angle (i) is around 40-50 degree, based on the measurements of all datasets. In the third dataset, a high black hole mass (M_BH) is strongly disfavored by the spectral fits. By unfreezing the black hole mass, we find a*>0.92, i=49.9^{+1.0}_{-1.3} degree and M_BH<8.0 Msun, at a 90% confidence level. Considering the lower limit derived from a previous optical constraint, M_BH is in a range of 4.9-8.0 Msun.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-10-26T02:28:06.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "hard intermediate state",
      "black hole grs",
      "black hole spin",
      "relativistic disk model kerrbb",
      "broad relativistic iron line"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 6,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}