Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· References in the article
· Citations to the Article (63) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (3)
· Also-Read Articles (Reads History)
· Translate This Page
Variations in the HCN/HNC abundance ratio in the Orion molecular cloud
Goldsmith, Paul F.; Irvine, William M.; Hjalmarson, Ake; Ellder, Joel
AA(Five College Radio Astronomy Observatory; Massachusetts, University, Amherst), AB(Five College Radio Astronomy Observatory; Massachusetts, University, Amherst), AC(Onsala Rymdobservatorium, Sweden), AD(Onsala Rymdobservatorium, Sweden)
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 310, Nov. 1, 1986, p. 383-391. Sponsorship: Naturvetenskapliga Forskningsradet of Sweden. (ApJ Homepage)
Publication Date:
NASA/STI Keywords:
Abundance, Hydrocyanic Acid, Isomers, Molecular Clouds, Orion Nebula, Periodic Variations, Data Processing, Interstellar Matter, Ratios, Spectrographs
Bibliographic Code:


Observations of the rare isotopes of HCN and HNC have been used to determine the relative abundance of these two chemical isomers along the central ridge of the Orion molecular cloud. The abundance ratio HCN/HNC decreases by more than an order of magnitude from the relatively warm plateau and hot core sources toward the KL nebula to the colder, more quiescent clouds to the north and south. Even in the cooler regions, however, the ratio is an order of magnitude larger than that found in previous investigations of cold dark clouds. The kinetic temperature in the regions studied is determined from new observations of methylacetylene (CH3CCH), together with other recent estimates of the gas temperature near KL. The results suggest that the warmer portions of the cloud are dominated by different chemical pathways that those in the general instellar cloud material.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences

More Article Retrieval Options

HELP for Article Retrieval

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)

Find Similar Abstracts:

Use: Authors
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
arXiv e-prints