{
  "id": "2104.14307",
  "version": "v1",
  "published": "2021-04-29T12:49:49.000Z",
  "updated": "2021-04-29T12:49:49.000Z",
  "title": "Detection of a low frequency quasi-periodic oscillation in the soft state of Cygnus X-1 with Insight-HXMT",
  "authors": [
    "Zhen Yan",
    "Stefano Rapisarda",
    "Wenfei Yu"
  ],
  "comment": "12 pages, 7 figures, 2 tables, submitted to ApJ",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We report the detection of a short-lived narrow quasi-periodic oscillation (QPO) at ~88 mHz in an Insight-HXMT observation during the soft state of the persistent black hole high mass X-ray binary Cygnus X-1. This QPO is significantly detected in all the three instruments of Insight-HXMT, so in the broad energy range 1-250 keV. The fractional RMS of the QPO does not show significant variations above 3 keV (~5%) while decreases at lower energy (~2%). We show that this QPO is different from the type-A, -B, and -C QPOs usually observed in black hole X-ray binaries. We compare QPOs at similar frequencies that have been previously detected in another persistent high mass X-ray binaries in the soft state, we speculate that such QPOs might relate to some local inhomogeneity rarely formed in the accretion flow of wind-fed accretion systems.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-04-29T12:49:49.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high mass x-ray binary",
      "low frequency quasi-periodic oscillation",
      "soft state",
      "hole high mass x-ray",
      "mass x-ray binary cygnus"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}