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Molecular line observations of the I ORI OB association including NGC 2068, NGC 2071 and the HH-24 region

White, G. J. and Phillips, J. P. (1981). Molecular line observations of the I ORI OB association including NGC 2068, NGC 2071 and the HH-24 region. Monthly Notices of the Royal Astronomical Society, 194 pp. 947–960.

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Molecular line observations of the giant molecular cloud associated with the northern Orion complex of the I Ori OB association are presented. An area of 1½ deg2 including the reflection nebulae NGC 2068 and NGC 2071, the Herbig-Haro complex M-78 HH and parts of the extended dust clouds L 1627 and L 1630 was surveyed in the CO and 13CO J = 1-0 lines at millimeter wavelengths. At least 12 molecular clouds are observed within the extended cloud, with CO intensity well correlated with regions of optical absorption. Intense molecular clouds are also observed close to NGC 2068 and NGC 2071, while the region surrounding the Herbig-Haro complex appears as a 5-K temperature enhancement. A velocity gradient of approximately 0.43 km s-1 pc-1 is observed across the cloud complex, indicating rotation about an axis lying along the minor axis of the northern Orion complex and at an angle of ~ 75° to the gradient plane.

Item Type: Journal Article
Copyright Holders: 1981 Royal Astronomical Society
ISSN: 1365-2966
Keywords: B stars; carbon monoxide; interstellar matter; line spectra; molecular clouds; O stars; anisotropy; astronomical models; carbon 13; emission spectra; hydrogen clouds; nebulae; Orion constellation; self absorption; velocity distribution
Academic Unit/Department: Science > Physical Sciences
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 33803
Depositing User: G. J. White
Date Deposited: 06 Jun 2012 12:19
Last Modified: 25 Feb 2016 00:52
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