{
  "id": "1007.1854",
  "version": "v1",
  "published": "2010-07-12T09:56:53.000Z",
  "updated": "2010-07-12T09:56:53.000Z",
  "title": "Ammonia and CO observations toward low-luminosity 6.7-GHz methanol masers",
  "authors": [
    "Y. W. Wu",
    "Y. Xu",
    "J. D. Pandian",
    "J. Yang",
    "C. Henkel",
    "K. M. Menten",
    "S. B. Zhang"
  ],
  "comment": "37 pages, 7 figures, 9 tables accepted by ApJ",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "To investigate whether distinctions exist between low and high-luminosity Class II 6.7-GHz methanol masers, we have undertaken multi-line mapping observations of various molecular lines, including the NH3(1,1), (2,2), (3,3), (4,4) and 12CO(1-0) transitions, towards a sample of 9 low-luminosity 6.7-GHz masers, and 12CO (1-0) observations towards a sample of 8 high-luminosity 6.7-GHz masers, for which we already had NH3 spectral line data. Emission in the NH3 (1,1), (2,2) and (3,3) transitions was detected in 8 out of 9 low-luminosity maser sources, in which 14 cores were identified. We derive densities, column densities, temperatures, core sizes and masses of both low and high-luminosity maser regions. Comparative analysis of the physical quantities reveals marked distinctions between the low-luminosity and high-luminosity groups: in general, cores associated with high-luminosity 6.7-GHz masers are larger and more massive than those traced by low-luminosity 6.7-GHz masers; regions traced by the high-luminosity masers have larger column densities but lower densities than those of the low-luminosity maser regions. Further, strong correlations between 6.7-GHz maser luminosity and NH3(1,1) and (2,2) line widths are found, indicating that internal motions in high-luminosity maser regions are more energetic than those in low-luminosity maser regions. A 12CO (1-0) outflow analysis also shows distinctions in that outflows associated with high-luminosity masers have wider line wings and larger sizes than those associated with low-luminosity masers.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2010-07-12T09:56:53.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "methanol masers",
      "low-luminosity maser regions",
      "high-luminosity maser regions",
      "nh3 spectral line data",
      "low-luminosity maser sources"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/720/1/392"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 37,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 860873,
      "adsabs": "2010arXiv1007.1854W"
    }
  }
}