{
  "id": "1711.03943",
  "version": "v1",
  "published": "2017-11-10T18:00:53.000Z",
  "updated": "2017-11-10T18:00:53.000Z",
  "title": "On the synchrotron spectrum of GRB prompt emission",
  "authors": [
    "Siyao Xu",
    "Yuan-Pei Yang",
    "Bing Zhang"
  ],
  "comment": "9 pages, 3 figures, submitted to ApJ on Oct. 23, 2017",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "The prompt emission spectrum of Gamma-ray bursts (GRB) is characterized by a smoothly joint broken power-law spectrum known as the Band function. The typical low-energy photon index is $\\sim -1$, which poses challenge to the standard synchrotron radiation models. We investigate the electron energy spectrum as a result of the interplay among adiabatic stochastic acceleration (ASA), particle injection, and synchrotron cooling. In the ASA-dominated low-energy range, ASA enables an efficient hardening of the injected energy spectrum to approach a spectral index $-1$. In the synchrotron cooling-dominated high-energy range, the injected high-energy electrons undergo fast synchrotron cooling and have a softer photon spectrum. With the energy range of the injected electrons broadly covering both the ASA- and synchrotron cooling-dominated ranges, the resulting photon number spectrum has the low- and high-energy indices as $\\alpha_s \\sim -1$ and $\\beta_s \\sim -p/2-1$, respectively. The break energy is of the order of $\\sim 100 $ keV, depending on the turbulence properties.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-11-10T18:00:53.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "grb prompt emission",
      "joint broken power-law spectrum",
      "synchrotron spectrum",
      "undergo fast synchrotron cooling",
      "high-energy electrons undergo fast synchrotron"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}