Fossil DCN in Orion-KL

Journal Article · Fri Mar 01 00:00:00 EST 1991 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169747· OSTI ID:5756883

Mangum, J G; Plambeck, R L; Wootten, A ^[1]

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1. Virginia Univ., Charlottesville (USA) California Univ., Berkeley (USA) National Radio Astronomy Observatory, Charlottesville, VA (USA)

The J = 1 - 0 transition of DCN was mapped toward Orion-KL with the BIMA array. With a synthesized beam width of 7.6 arcsec, emission from the hot core, compact ridge, and northern cloud regions was identified. Over half of the integrated DCN emission detected originates from the hot core component, with progressively smaller contributions from the compact ridge and northern cloud. The DCN fractional abundance is 10 to the -9th in the hot core, 4 x 10 to the -10th in the compact ridge, and 2 x 10 to the -10th in the northern cloud; it is estimated that the corresponding DCN/HCN ratios are about 0.005, 0.02, and 0.02. Chemical models suggest that such high DCN/HCN abundance ratios are produced only in clouds colder than about 20 K. Since the present temperatures near Orion-KL are 50-275 K, it is evident that most of the DCN formed before this region was heated by massive star formation. Much of the fossil DCN which is now observed may have sublimated from icy grain mantles. 32 refs.

• OSTI ID: 5756883
• Journal Information: Astrophysical Journal; (USA), Vol. 369; ISSN 0004-637X
• Country of Publication: United States
• Language: English

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71 CLASSICAL AND QUANTUM MECHANICS
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COSMIC GASES
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GROUND STATES
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640105* - Astrophysics & Cosmology- Galaxies