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Observations of the J = 2 → 1 line of carbon monoxide in the NGC 2024 nebula

Watt, G. D.; White, G. J.; Cronin, N. J. and van Vliet, A. H. F. (1979). Observations of the J = 2 → 1 line of carbon monoxide in the NGC 2024 nebula. Monthly Notices of the Royal Astronomical Society, 189 pp. 287–291.

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Observations have been made of the J = 2 → 1 transition of 12CO and 13CO in the molecular cloud near NGC 2024. The most intense emission comes from the central regions of the nebula close to areas of high optical extinction. The source contains two hotspots, but no significant velocity gradient or line-broadening was observed. This is consistent with a model in which the emission arises mainly from the high-density interface between the expanding HII region and a neutral cloud. Measurements of the 13CO isotope indicates that τ13 > 1.7, but there is insufficient information to derive the density in the region. Analysis of data for Mon R2, however, using the radially collapsing cloud model, indicates a hydrogen density of ~2 × 104 cm-3 for that source.

Item Type: Journal Item
Copyright Holders: 1979 Royal Astronomical Society
ISSN: 1365-2966
Keywords: carbon monixide; emission spectra; hydrogen clouds; interstellar gas; molecular spectra; nebulae; astronomical maps; astronomical models; carbon isotopes; infrared spectra; spectral line width
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Item ID: 33277
Depositing User: G. J. White
Date Deposited: 28 Mar 2012 13:15
Last Modified: 08 Dec 2018 20:21
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