{
  "id": "1711.08577",
  "version": "v1",
  "published": "2017-11-23T05:16:19.000Z",
  "updated": "2017-11-23T05:16:19.000Z",
  "title": "A more stringent constraint on the mass ratio of binary neutron star merger GW170817",
  "authors": [
    "He Gao",
    "Zhoujian Cao",
    "Shunke Ai",
    "Bing Zhang"
  ],
  "comment": "6 pages, 3 figures",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "Recently, the LIGO-Virgo collaboration reported their first detection of gravitational wave (GW) signals from a low mass compact binary merger GW170817, which is most likely due to a double neutron star (NS) merger. With the GW signals only, the chirp mass of the binary is precisely constrained to $1.188^{+0.004}_{-0.002}~\\rm{M_{\\odot}}$, but the mass ratio is loosely constrained in the range $0.4-1$, so that a very rough estimation of the individual NS masses ($0.86~{\\rm M_{\\odot}}<M_1<1.36~\\rm{M_{\\odot}}$ and $1.36~{\\rm M_{\\odot}}<M_2<2.26~\\rm{M_{\\odot}}$) was obtained. Here we propose that if one can constrain the dynamical ejecta mass through performing kilonova modeling of the optical/IR data, by utilizing an empirical relation between the dynamical ejecta mass and the mass ratio of NS binaries, one may place a more stringent constraint on the mass ratio of the system. For instance, considering that the red \"kilonova\" component is powered by the dynamical ejecta, we reach a tight constraint on the mass ratio in the range of $0.46-0.59$. Alternatively, if the blue \"kilonova\" component is powered by the dynamical ejecta, the mass ratio would be constrained in the range of $0.53-0.67$. Overall, such a multi-messenger approach could narrow down the mass ratio of GW170817 system to the range of $0.46-0.67$, which gives a more precise estimation of the individual NS mass than pure GW signal analysis, i.e. $0.90~{\\rm M_{\\odot}}<M_1<1.16~{\\rm M_{\\odot}}$ and $1.61~{\\rm M_{\\odot}}<M_2<2.11~{\\rm M_{\\odot}}$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-11-23T05:16:19.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "binary neutron star merger gw170817",
      "mass ratio",
      "stringent constraint",
      "compact binary merger gw170817",
      "mass compact binary merger"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 6,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}