{
  "id": "astro-ph/0410572",
  "version": "v2",
  "published": "2004-10-24T12:57:32.000Z",
  "updated": "2005-06-07T05:59:51.000Z",
  "title": "High Resolution Observations of the Near-Infrared Emission from NGC 6822 Hubble V",
  "authors": [
    "Sungho Lee",
    "Soojong Pak",
    "Sang-Gak Lee",
    "Christopher J. Davis",
    "Michael J. Kaufman",
    "Kenji Mochizuki",
    "Daniel T. Jaffe"
  ],
  "comment": "9 pages, 3 figures, MNRAS in press, Replacement: much condensation in the length but small change in the conclusions",
  "journal": "Mon.Not.Roy.Astron.Soc. 361 (2005) 1273-1280",
  "doi": "10.1111/j.1365-2966.2005.09259.x",
  "categories": [
    "astro-ph"
  ],
  "abstract": "We observed Hubble V, the brightest HII region complex in the dwarf irregular galaxy NGC 6822, at near-infrared (1.8--2.4 um) wavelengths using the Cooled Grating Spectrometer 4 (CGS4) at the United Kingdom Infra-Red Telescope (UKIRT). The line emission maps of Hubble V show the typical structure of a photo-dissociation region (PDR) where an ionized core, traced by compact He I emission (2.0587 um) and Br_gamma emission (2.1661 um), is surrounded by an outer layer traced by molecular hydrogen (H_2) emission. The measured line ratios of H_2 2-1 S(1) (2.2477 um) / 1-0 S(1) (2.1218 um) from 0.2 to 0.6 and the un-shifted and un-resolved line profiles suggest that the H_2 emission originates purely from a PDR. By comparing the H_2 results with a PDR model, we conclude that Hubble V includes dense (10^{4.5} cm^{-3}) and warm PDRs. In this environment, most of the H_2 molecules are excited by far-UV photons (with a field strength of 10^{2-4} times that of the average interstellar field), although collisional processes de-excite H_2 and contribute significantly to the excitation of the first vibrational level. We expect that Hubble V is in the early stage of molecular cloud dissolution.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2005-06-07T05:59:51.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high resolution observations",
      "near-infrared emission",
      "dwarf irregular galaxy ngc",
      "brightest hii region complex",
      "molecular cloud dissolution"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "Wiley-Blackwell",
      "journal": "J. Finance"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 662674
    }
  }
}