{
  "id": "2303.12616",
  "version": "v1",
  "published": "2023-03-22T14:57:03.000Z",
  "updated": "2023-03-22T14:57:03.000Z",
  "title": "The orbital and physical properties of five southern Be+sdO binary systems",
  "authors": [
    "Luqian Wang",
    "Douglas R. Gies",
    "Geraldine J. Peters",
    "Zhanwen Han"
  ],
  "comment": "50 pages, 23 figures, 16 tables",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "Close binary interactions may play a critical role in the formation of the rapidly rotating Be stars. Mass transfer can result in a mass gainer star spun up by the accretion of mass and angular momentum, while the mass donor is stripped of its envelope to form a hot and faint helium star. FUV spectroscopy has led to the detection of about 20 such binary Be+sdO systems. Here we report on a three-year program of high quality spectroscopy designed to determine the orbital periods and physical properties of five Be binary systems. These binaries are long orbital period systems with $P =$ 95 to 237 days and with small semi-amplitude $K_1<11$ km s$^{-1}$. We combined the Be star velocities with prior sdO measurements to obtain mass ratios. A Doppler tomography algorithm shows the presence of the He II $\\lambda 4686$ line in the faint spectrum of the hot companion in four of the targets. We discuss the observed line variability and show evidence of phased-locked variations in the emission profiles of HD 157832, suggesting a possible disk spiral density wave due to the presence of the companion star. The stripped companions in HD 113120 and HD 137387 may have a mass larger than the 1.4 $M_\\odot$ indicating that they could be progenitors of Type Ib and Ic supernovae.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-03-22T14:57:03.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "binary systems",
      "physical properties",
      "disk spiral density wave",
      "mass gainer star spun",
      "long orbital period systems"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 50,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}