{
  "id": "astro-ph/0405049",
  "version": "v1",
  "published": "2004-05-04T12:01:27.000Z",
  "updated": "2004-05-04T12:01:27.000Z",
  "title": "Galactic Evolution of Nitrogen",
  "authors": [
    "G. Israelian",
    "A. Ecuvillon",
    "R. Rebolo",
    "R. Garcia Lopez",
    "P. Bonifacio",
    "P. Molaro"
  ],
  "comment": "10 pages, 6 figures, to appear in Astronomy and Astrophysics",
  "journal": "Astron.Astrophys. 421 (2004) 649-658",
  "doi": "10.1051/0004-6361:20047132",
  "categories": [
    "astro-ph"
  ],
  "abstract": "We present detailed spectroscopic analysis of nitrogen abundances in 31 unevolved metal-poor stars analysed by spectral synthesis of the near-UV NH band at 3360 A observed at high resolution with various telescopes. We found that [N/Fe] scales with that of iron in the metallicity range -3.1 < [Fe/H] <0 with the slope 0.01+-0.02. Furthermore, we derive uniform and accurate (N/O) ratios using oxygen abundances from near-UV OH lines obtained in our previous studies. We find that a primary component of nitrogen is required to explain the observations. The NH lines are discovered in the VLT/UVES spectra of the very metal-poor subdwarfs G64-12 and LP815-43 indicating that these stars are N rich. The results are compared with theoretical models and observations of extragalactic HII regions and Damped Ly$\\alpha$ systems. This is the first direct comparison of the (N/O) ratios in these objects with those in Galactic stars.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2004-05-04T12:01:27.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "galactic evolution",
      "first direct comparison",
      "extragalactic hii regions",
      "near-uv nh band",
      "near-uv oh lines"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 649593
    }
  }
}