{
  "id": "2205.09675",
  "version": "v1",
  "published": "2022-05-19T16:34:30.000Z",
  "updated": "2022-05-19T16:34:30.000Z",
  "title": "Fermi-LAT detection of a GeV afterglow from a compact stellar merger",
  "authors": [
    "Hai-Ming Zhang",
    "Yi-Yun Huang",
    "Jian-He Zheng",
    "Ruo-Yu Liu",
    "Xiang-Yu Wang"
  ],
  "comment": "1 table, 3 figures",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "It is usually thought that long-duration gamma-ray bursts (GRBs) are associated with massive star core collapse whereas short-duration GRBs are associated with mergers of compact stellar binaries. The discovery of a kilonova associated with a nearby (350 Mpc) long-duration GRB- GRB 211211A, however, indicates that the progenitor of this long-duration GRB is a compact object merger. Here we report the \\emph{Fermi}-LAT detection of gamma-ray ($>100 {\\rm \\ MeV}$) afterglow emission from GRB 211211A, which lasts $\\sim 20000$ s after the burst, the longest event for conventional short-duration GRBs ever detected. We suggest that this gamma-ray emission results mainly from afterglow synchrotron emission. The soft spectrum of GeV emission may arise from a limited maximum synchrotron energy of only a few hundreds of MeV at $\\sim 20000$ s. The usually long duration of the GeV emission could be due to the proximity of this GRB and the long deceleration time of the GRB jet that is expanding in a low density cricumburst medium, consistent with the compact stellar merger scenario.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-05-19T16:34:30.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "gev afterglow",
      "fermi-lat detection",
      "compact stellar merger scenario",
      "low density cricumburst medium",
      "gev emission"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}