{
  "id": "1608.06297",
  "version": "v1",
  "published": "2016-08-22T20:01:14.000Z",
  "updated": "2016-08-22T20:01:14.000Z",
  "title": "Variability study of the High Mass X-ray Binary IGR J18027--2016 with {\\it Swift}--XRT",
  "authors": [
    "Nafisa Aftab",
    "Nazma Islam",
    "Biswajit Paul"
  ],
  "comment": "Accepted for publication in MNRAS, Comments are welcome",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We report the results from pulsations and spectral analysis of a large number of observations of the HMXB pulsar IGR J18027--2016 with {\\it Swift}--XRT, carried out at different orbital phases. In some orbital phases, as seen in different XRT observations, the X-ray intensity is found to vary by a large factor, of about $\\sim$50. In all the observations with sufficient number of source X-ray photons, pulsations have been detected around the previously known pulse period of $\\sim$140 sec, When detected, the pulse profiles do not show any significant variation over a flux difference of a factor of $\\sim$3. The absorption column density is found to be large before and after the eclipse. We discuss various possible reasons for intensity and spectral variations in IGR J18027--2016, such as clumpy wind and hydrodynamic instabilities.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-08-22T20:01:14.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high mass x-ray binary igr",
      "variability study",
      "orbital phases",
      "hmxb pulsar igr",
      "absorption column density"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}