{
  "id": "2102.09498",
  "version": "v1",
  "published": "2021-02-18T17:29:22.000Z",
  "updated": "2021-02-18T17:29:22.000Z",
  "title": "QPOs and Orbital elements of X-ray binary 4U 0115+63 during the 2017 outburst observed by Insight-HXMT",
  "authors": [
    "Y. Z. Ding",
    "W. Wang",
    "P. Zhang",
    "Q. C. Bu",
    "C. Cai",
    "X. L. Cao",
    "C. Zhi",
    "L. Chen",
    "T. X. Chen",
    "Y. B. Chen",
    "Y. Chen",
    "Y. P. Chen",
    "W. W. Cui",
    "Y. Y. Du",
    "G. H. Gao",
    "H. Gao",
    "M. Y. Ge",
    "Y. D. Gu",
    "J. Guan",
    "C. C. Guo",
    "D. W. Han",
    "Y. Huang",
    "J. Huo",
    "S. M. Jia",
    "W. C. Jiang",
    "J. Jin",
    "L. D. Kong",
    "B. Li",
    "C. K. Li",
    "G. Li",
    "T. P. Li",
    "W. Li",
    "X. Li",
    "X. B. Li",
    "X. F. Li",
    "Z. W. Li",
    "X. H. Liang",
    "J. Y. Liao",
    "B. S. Liu",
    "C. Z. Liu",
    "H. X. Liu",
    "H. W. Liu",
    "X. J. Liu",
    "F. J. Lu",
    "X. F. Lu",
    "Q. L.",
    "L. T.",
    "R. C. Ma",
    "X. Ma",
    "B. Meng",
    "Y. Nang",
    "J. Y. Nie",
    "J. L. Qu",
    "X. Q. Ren",
    "N. Sai",
    "L. M. Song",
    "X. Y. Song",
    "L. Sun",
    "Y. Tan",
    "L. Tao",
    "Y. L. Tuo",
    "L. J. Wang",
    "P. J. Wang",
    "W. S. Wang",
    "Y. S. Wang",
    "X. Y. Wen",
    "B. Y. Wu",
    "B. B. Wu",
    "M. Wu",
    "G. C. Xiao",
    "S. Xiao",
    "S. L. Xiong",
    "Y. P. Xu",
    "R. J. Yang",
    "S. Yang",
    "Y. J. Yang",
    "Q. B. Yi",
    "Q. Q. Yin",
    "Y. You",
    "F. Zhang",
    "H. M. Zhang",
    "J. Zhang",
    "P. Zhang",
    "S. Zhang",
    "S. N. Zhang",
    "W. C. Zhang",
    "W. Zhang",
    "Y. F. Zhang",
    "Y. H. Zhang",
    "H. S. Zhao",
    "X. F. Zhao",
    "S. J. Zheng",
    "Y. G. Zheng",
    "D. K. Zhou"
  ],
  "comment": "14 pages, 9 figures, and 6 tables. This work has been submitted to MNRAS after the referee's report",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "In this paper, we presented a detailed timing analysis of a prominent outburst of 4U 0115+63 detected by \\textit{Insight}-HXMT in 2017 August. The spin period of the neutron star was determined to be $3.61398\\pm 0.00002$ s at MJD 57978. We measured the period variability and extract the orbital elements of the binary system. The angle of periastron evolved with a rate of $0.048\\pm0.003$ $yr^{-1}$. The light curves are folded to sketch the pulse profiles in different energy ranges. A multi-peak structure in 1-10 keV is clearly illustrated. We introduced wavelet analysis into our data analysis procedures to study QPO signals and perform a detailed wavelet analysis in many different energy ranges. Through the wavelet spectra, we report the discovery of a QPO at the frequency $\\sim 10$ mHz. In addition, the X-ray light curves showed multiple QPOs in the period of $\\sim 16-32 $ s and $\\sim 67- 200 $ s. We found that the $\\sim100$ s QPO was significant in most of the observations and energies. There exist positive relations between X-ray luminosity and their Q-factors and S-factors, while the QPO periods have no correlation with X-ray luminosity. In wavelet phase maps, we found that the pulse phase of $\\sim 67- 200 $ s QPO drifting frequently while the $\\sim 16-32 $ s QPO scarcely drifting. The dissipation of oscillations from high energy to low energy was also observed. These features of QPOs in 4U 0115+63 provide new challenge to our understanding of their physical origins.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-02-18T17:29:22.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "x-ray binary 4u",
      "orbital elements",
      "light curves showed multiple",
      "curves showed multiple qpos",
      "x-ray luminosity"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}