{
  "id": "2209.13493",
  "version": "v1",
  "published": "2022-09-27T16:14:35.000Z",
  "updated": "2022-09-27T16:14:35.000Z",
  "title": "Investigation of a likely orbital periodicity of Nova Hercules 2021 in X-rays and gamma-rays",
  "authors": [
    "Lupin Chun-Che Lin",
    "Jhih-Ling Fan",
    "Chin-Ping Hu",
    "Jumpei Takata",
    "Kwan-Lok Li"
  ],
  "comment": "5 pages and 5 figures, accepted by MNRAS letter",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We report a detection of a 0.153 days period in the classical nova V1674 Her using the NICER observations taken within a month since the outburst (i.e., about MJD 59405). The X-ray period is consistent with the orbital period previously found in the optical band, strongly suggesting the NICER signal as the X-ray orbital periodicity of the system. A seemingly double-humped profile was obtained by folding the detrended X-ray light curve with the period after removing the rotational X-ray pulsations of the nova. The profile may be caused by occultation by the companion or the accretion disk, possibly indicating a high inclination of the system. The gamma-ray emission of V1674 Her with a significance level > 5 sigma was detected by Fermi-LAT close to its optical peak and the emission faded away within 1 day, which is the shortest duration known for a gamma-ray nova. Folded on 0.153days, a marginal gamma-ray variability can be also seen in the LAT light curve, but without the double-hump feature observed in X-rays. If the gamma-ray modulation is real, its origin is probably different from that observed in the X-ray and optical bands.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-09-27T16:14:35.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "nova hercules",
      "investigation",
      "marginal gamma-ray variability",
      "rotational x-ray pulsations",
      "detrended x-ray light curve"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}