{
  "id": "1007.1552",
  "version": "v1",
  "published": "2010-07-09T10:30:48.000Z",
  "updated": "2010-07-09T10:30:48.000Z",
  "title": "New Fe II energy levels from stellar spectra",
  "authors": [
    "Fiorella Castelli",
    "Robert L. Kurucz"
  ],
  "comment": "paper accepted by A&A--this version differs from the previous one for a correction of the English and for the splitting of a paragraph in Sect. 3 into two paragraphs",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "The spectra of B-type and early A-type stars show mumerous unidentified lines in the whole optical range, especially in the 5100-5400 A interval. Because Fe II transitions to high energy levels should be observed in this region, we used semiempirical predicted wavelengths and gf-values of Fe II to identify unknown lines. Semiempirical line data for Fe II computed by Kurucz are used to synthesize the spectrum of the slow-rotating, Fe-overabundant CP star HR 6000. We determined a total of 109 new 4f levels for Fe II with energies ranging from 122324 cm^-1 to 128110 cm^-1. They belong to the Fe II subconfigurations 3d^6(^3P)4f (10 levels), 3d^6(^3H)4f (36 levels), 3d^6(^3F)4f (37 levels), and 3d^6(^3G)4f (26 levels). We also found 14 even levels from 4d (3 levels), 5d (7 levels), and 6d (4 levels) configurations. The new levels have allowed us to identify more than 50% of the previously unidentified lines of HR 6000 in the wavelength region 3800-8000 A. Tables listing the new energy levels are given in the paper; tables listing the spectral lines with log gf >/= -1.5 that are transitions to the 4f energy levels are given in the Online Material. These new levels produce 18000 lines throughout the spectrum from the ultraviolet to the infrared.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2010-07-09T10:30:48.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "stellar spectra",
      "fe-overabundant cp star hr",
      "4f energy levels",
      "unidentified lines",
      "high energy levels"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 861050,
      "adsabs": "2010arXiv1007.1552C"
    }
  }
}