{
  "id": "1603.02277",
  "version": "v1",
  "published": "2016-03-07T21:00:07.000Z",
  "updated": "2016-03-07T21:00:07.000Z",
  "title": "[CII] emission in z ~ 6 strongly lensed, star-forming galaxies",
  "authors": [
    "Kirsten K. Knudsen",
    "Johan Richard",
    "Jean-Paul Kneib",
    "Mathilde Jauzac",
    "Benjamin Clement",
    "Guillaume Drouart",
    "Eiichi Egami",
    "Lukas Lindroos"
  ],
  "comment": "5 pages, submitted to MNRAS",
  "categories": [
    "astro-ph.GA",
    "astro-ph.CO"
  ],
  "abstract": "The far-infrared fine-structure line [CII] at 1900.5GHz is known to be one of the brightest cooling lines in local galaxies, and therefore it has been suggested to be an efficient tracer for star-formation in very high-redshift galaxies. However, recent results for galaxies at $z>6$ have yielded numerous non-detections in star-forming galaxies, except for quasars and submillimeter galaxies. We report the results of ALMA observations of two lensed, star-forming galaxies at $z = 6.029$ and $z=6.703$. The galaxy A383-5.1 (star formation rate [SFR] of 3.2 M$_\\odot$yr$^{-1}$ and magnification of $\\mu = 11.4$) shows a line detection with $L_{\\rm [CII]} = 8.3\\times10^{6}$ L$_\\odot$, making it the so far lowest $L_{\\rm [CII]}$ ever detected at $z>6$. For MS0451-H (SFR = 0.4M$_\\odot$yr$^{-1}$ and $\\mu = 100\\pm20$) we provide an upper limit of $L_{\\rm [CII]} < 3\\times10^{5}$ L$_\\odot$, which is 1\\,dex below the local SFR-$L_{\\rm [CII]}$ relations. The results are consistent with predictions for low-metallicity galaxies at $z>6$, however, other effects could also play a role in terms of decreasing $L_{\\rm [CII]}$. The detection of A383-5.1 is encouraging and suggests that detections are possible, but much fainter than initially predicted.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-03-07T21:00:07.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "star-forming galaxies",
      "star formation rate",
      "efficient tracer",
      "high-redshift galaxies",
      "far-infrared fine-structure line"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2016arXiv160302277K",
      "inspire": 1426653
    }
  }
}