{
  "id": "astro-ph/9903023",
  "version": "v1",
  "published": "1999-03-01T21:47:25.000Z",
  "updated": "1999-03-01T21:47:25.000Z",
  "title": "A Possible Explanation for the Radio ``Flare'' in the Early Afterglow of GRB990123",
  "authors": [
    "Xiangdong Shi",
    "Geza Gyuk"
  ],
  "comment": "14 pages including 3 figures, submitted to ApJL",
  "categories": [
    "astro-ph"
  ],
  "abstract": "We suggest that the deceleration of the relativistic shock by a denser part of the interstellar medium off line-of-sight produced the observed radio ``flare'' in the early afterglow of GRB990123. We find that this scenario is consistent with observations if the particle number density of this denser part of the medium is between $\\sim 200$ and $\\sim 2\\times 10^4$ cm$^{-3}$. Because of the premature deceleration of part of the shock, the later stage of the afterglow should decay modestly faster than the powerlaw expected from an isotropic shock propagation.",
  "revisions": [
    {
      "version": "v1",
      "updated": "1999-03-01T21:47:25.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "early afterglow",
      "explanation",
      "denser part",
      "particle number density",
      "isotropic shock propagation"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 496029,
      "adsabs": "1999astro.ph..3023S"
    }
  }
}