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 (57) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (7)
· Also-Read Articles (Reads History)
· Translate This Page
Interstellar absorption lines toward NGC 2264 and AFGL 2591 - Abundances of H2, H3(+), and CO
Black, John H.; van Dishoeck, Ewine F.; Willner, Steven P.; Woods, R. Claude
AA(Steward Observatory, Tucson, AZ), AB(California Institute of Technology, Pasadena), AC(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA), AD(Wisconsin, University, Madison)
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 358, Aug. 1, 1990, p. 459-467. Research supported by NSF. (ApJ Homepage)
Publication Date:
NASA/STI Keywords:
Absorption Spectra, Abundance, Galactic Cosmic Rays, Interstellar Gas, Line Spectra, Carbon Monoxide, Hydrogen, Infrared Spectra, Infrared Spectrophotometers, Interstellar Matter, Stellar Spectrophotometry
Bibliographic Code:


Interstellar absorption-line spectroscopy of NGC 2264 is reported which shows that the CO molecule has a column density of 5 x 10 to the 18th/sq cm and a rotational excitation temperature of 28 K. A direct upper limit on the H2 column density implies that at least 6 percent of a solar carbon abundance is in the form of CO. The upper limit on the H3(+) abundance implies that the cosmic-ray ionization rate is of the order of 10 to the -16th/s or less. The H3(+) upper limit, together with a previous radio detection of H2D(+) emission, implies either an enormous overabundance of the deuterated molecule or else that most of the radio emission comes from clouds not located directly between use and the infrared source. Observations of the sources AFGL 2591 and NGC 2024 IRS2 indicate that upper limits on H3(+) imply cosmic ray ionization rates of less than 3 and 60 x 10 to the -17th/s, respectively.

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