{
  "id": "2104.13472",
  "version": "v1",
  "published": "2021-04-27T20:59:19.000Z",
  "updated": "2021-04-27T20:59:19.000Z",
  "title": "AstroSat observation of the HBL 1ES 1959+650 during its October 2017 flaring",
  "authors": [
    "Zahir Shah",
    "Savithri H. Ezhikode",
    "Ranjeev Misra",
    "Rajalakshmi T. R"
  ],
  "comment": "13 pages, 7 figures, 3 tables. Accepted for publication in MNRAS",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present the results of the X-ray flaring activity of 1ES 1959+650 during October 25-26, 2017 using AstroSat observations. The source was variable in the X-ray. We investigated the evolution of the X-ray spectral properties of the source by dividing the total observation period ($\\sim 130$ ksecs) into time segments of 5 ksecs, and fitting the SXT and LAXPC spectra for each segment. Synchrotron emission of a broken power-law particle density model provided a better fit than the log-parabola one. The X-ray flux and the normalised particle density at an energy less than the break one, were found to anti-correlate with the index before the break. However, a stronger correlation between the density and index was obtained when a delay of $\\sim 60$ ksec was introduced. The amplitude of the normalised particle density variation $|\\Delta n_\\gamma/n_\\gamma| \\sim 0.1$ was found to be less than that of the index $\\Delta \\Gamma \\sim 0.5$. We model the amplitudes and the time delay in a scenario where the particle acceleration time-scale varies on a time-scale comparable to itself. In this framework, the rest frame acceleration time-scale is estimated to be $\\sim 1.97\\times10^{5}$ secs and the emission region size to be $\\sim 6.73\\times 10^{15}$ cms.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-04-27T20:59:19.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "astrosat observation",
      "hbl 1es",
      "normalised particle density",
      "broken power-law particle density model",
      "particle acceleration time-scale varies"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 13,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}