{
  "id": "1403.5601",
  "version": "v1",
  "published": "2014-03-22T02:02:41.000Z",
  "updated": "2014-03-22T02:02:41.000Z",
  "title": "CIR Modulation of the X-ray Flux from the O7.5 III(n)((f)) Star xi Persei?",
  "authors": [
    "D. Massa",
    "L. Oskinova",
    "A. W. Fullerton",
    "R. K. Prinja",
    "D. A. Bohlender",
    "N. D. Morrison",
    "M. Blake",
    "W. Pych"
  ],
  "comment": "Accepted by MNRAS. 9 pages, 9 figures",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "We analyze a 162 ks HETG Chandra observation of the O7.5 III(n)((f)) star xi Per, together with contemporaneous H alpha observations. The X-ray spectrum of this star is similar to other single O stars, and not pathological in any way. Its UV wind lines are known to display cyclical time variability, with a period of 2.086 days, which is thought to be associated with co-rotating interaction regions (CIRs). We examine the Chandra and H alpha data for variability on this time scale. We find that the X-rays vary by about 15% over the course of the observations and that this variability is out of phase with variable absorption on the blue wing of the H alpha profiles (assumed to be a surrogate for the UV absorption associated with CIRs). While not conclusive, both sets of data are consistent with models where the CIRs are either a source of X-rays or modulate them.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2014-03-22T02:02:41.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "star xi persei",
      "x-ray flux",
      "cir modulation",
      "ks hetg chandra observation",
      "uv wind lines"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1093/mnras/stu565",
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2014,
      "month": "Jul",
      "volume": 441,
      "number": 3,
      "pages": 2173
    },
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2014MNRAS.441.2173M"
    }
  }
}