{
  "id": "2303.03742",
  "version": "v1",
  "published": "2023-03-07T09:03:47.000Z",
  "updated": "2023-03-07T09:03:47.000Z",
  "title": "Evolution of low frequency quasi-periodic oscillations in GX\\,339--4 during its 2021 outburst using {\\it AstroSat} data",
  "authors": [
    "Santanu Mondal",
    "Anirudh Salgundi",
    "Debjit Chatterjee",
    "Arghajit Jana",
    "H. -K. Chang",
    "Sachindra Naik"
  ],
  "comment": "5 pages, 5 figures, 2 tables, submitted, comments welcome",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "The black hole X-ray binary GX\\,339-4 showed an X-ray outburst during 2021. The {\\it AstroSat} captured this outburst when the source entered into the intermediate flux state, while the count rate was declining. The source showed an alternating flux profile in a timescale of $\\lesssim$100 ks, where the hard energy band was more variable than the soft band. The energy dependent timing study showed that the observed quasi-periodic oscillation (QPO) was prominent in the low energy bands, with its sub-harmonic and harmonic components. These components appear and disappear with time, which is observed in the orbit-wise QPO study. The rms spectra of all orbits exhibiting QPOs show its maximum amplitude $\\sim$ 10 keV, may indicate that mostly 10 keV photons participated in originating QPOs. The energy-dependent time lag agrees its association and origin with the Comptonising corona. Finally, we discuss possible reasons behind the origin of different timing properties observed.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-03-07T09:03:47.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "low frequency quasi-periodic oscillations",
      "black hole x-ray binary",
      "low energy bands",
      "energy dependent timing study"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}