{
  "id": "1203.6852",
  "version": "v1",
  "published": "2012-03-30T16:35:41.000Z",
  "updated": "2012-03-30T16:35:41.000Z",
  "title": "Ionized nitrogen at high redshift",
  "authors": [
    "R. Decarli",
    "F. Walter",
    "R. Neri",
    "F. Bertoldi",
    "C. Carilli",
    "P. Cox",
    "J. P. Kneib",
    "J. F. Lestrade",
    "R. Maiolino",
    "A. Omont",
    "J. Richard",
    "D. Riechers",
    "K. Thanjavur",
    "A. Weiss"
  ],
  "comment": "5 Figures, 1 Table. Accepted for publication in ApJ",
  "categories": [
    "astro-ph.CO"
  ],
  "abstract": "We present secure [NII[ detections in two mm-bright, strongly lensed objects at high redshift, APM08279+5255 (z=3.911) and MM18423+5938 (z=3.930), using the IRAM Plateau de Bure Interferometer. Due to its ionization energy [NII] is a good tracer of the ionized gas phase in the interstellar medium. The measured fluxes are S([NII])=(4.8+/-0.8) Jy km/s and (7.4+/-0.5) Jy km/s respectively, yielding line luminosities of L([NII]) =(1.8+/-0.3) x 10^9 \\mu^{-1} Lsun for APM08279+5255 and L([NII]) =(2.8+/-0.2) x 10^9 \\mu^{-1} Lsun for MM18423+5938. Our high-resolution map of the [NII] and 1 mm continuum emission in MM18423+5938 clearly resolves an Einstein ring in this source, and reveals a velocity gradient in the dynamics of the ionized gas. A comparison of these maps with high-resolution EVLA CO observations enables us to perform the first spatially-resolved study of the dust continuum-to-molecular gas surface brightness (Sigma_{FIR} Sigma_{CO}^N, which can be interpreted as the star formation law) in a high-redshift object. We find a steep relation (N=1.4+/-0.2), consistent with a starbursting environment. We measure a [NII]/FIR luminosity ratio in APM0828+5255 and MM18423+5938 of 9.0 x 10^{-6} and 5.8 x 10^{-6}, respectively. This is in agreement with the decrease of the [NII]/FIR ratio at high FIR luminosities observed in local galaxies.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2012-03-30T16:35:41.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high redshift",
      "ionized nitrogen",
      "dust continuum-to-molecular gas surface brightness",
      "jy km/s",
      "star formation law"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/752/1/2",
      "journal": "The Astrophysical Journal",
      "year": 2012,
      "month": "Jun",
      "volume": 752,
      "number": 1,
      "pages": 2
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1095478,
      "adsabs": "2012ApJ...752....2D"
    }
  }
}