{
  "id": "1009.1432",
  "version": "v3",
  "published": "2010-09-08T01:01:28.000Z",
  "updated": "2011-03-15T03:14:37.000Z",
  "title": "On the High Energy Emission of the Short GRB 090510",
  "authors": [
    "Hao-Ning He",
    "Xue-Feng Wu",
    "Kenji Toma",
    "Xiang-Yu Wang",
    "Peter Meszaros"
  ],
  "comment": "29 pages, 2 figures; Accepted for publication in ApJ",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "Long-lived high-energy (>100MeV) emission, a common feature of most Fermi-LAT detected gamma-ray burst, is detected up to \\sim 10^2 s in the short GRB 090510. We study the origin of this long-lived high-energy emission, using broad-band observations including X-ray and optical data. We confirm that the late > 100 MeV, X-ray and optical emission can be naturally explained via synchrotron emission from an adiabatic forward shock propagating into a homogeneous ambient medium with low number density. The Klein-Nishina effects are found to be significant, and effects due to jet spreading and magnetic field amplification in the shock appear to be required. Under the constraints from the low-energy observations, the adiabatic forward shock synchrotron emission is consistent with the later-time (t>2s) high-energy emission, but falls below the early-time (t < 2s) high energy emission. Thus we argue that an extra high energy component is needed at early times. A standard reverse shock origin is found to be inconsistent with this extra component. Therefore, we attribute the early part of the high-energy emission (t< 2s) to the prompt component, and the long-lived high energy emission (t>2s) to the adiabatic forward shock synchrotron afterglow radiation. This avoids the requirement for an extremely high initial Lorentz factor.",
  "revisions": [
    {
      "version": "v3",
      "updated": "2011-03-15T03:14:37.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high energy emission",
      "short grb",
      "high initial lorentz factor",
      "shock synchrotron afterglow radiation",
      "adiabatic forward shock synchrotron"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/733/1/22",
      "journal": "The Astrophysical Journal",
      "year": 2011,
      "month": "May",
      "volume": 733,
      "number": 1,
      "pages": 22
    },
    "note": {
      "typesetting": "TeX",
      "pages": 29,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 868045,
      "adsabs": "2011ApJ...733...22H"
    }
  }
}