On the nature of the molecular cores in high-latitude cirrus clouds. I. A survey of H sub 2 CO (2 centimeter), C3H2, and HC3N

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/167797· OSTI ID:5250704

Turner, B E; Richard, L J; Xu, Lanping ^[1]

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1. National Radio Astronomy Observatory, Charlottesville, VA (USA)

The 2-cm H{sub 2}CO emission has been detected in 12 of the 28 core regions surveyed in 15 different high-latitude cirrus complexes, together with the C{sub 3}H{sub 2} line in 16 of the cores and, possibly, the HC{sub 3}N line in two of the cores. The fractional abundances of H{sub 2}CO, C{sub 3}H{sub 2}, and HC{sub 3}N, are noted to be at least an order of magnitude lower than those of Galactic plane dark clouds; the derived extinctions are higher than previous high resolution estimates, suggesting that external UV fields play only a minor role in either the chemistry or the grain heating. A low metallicity for the cirrus cores is suggested as the basis for the observed low fractional abundances. 57 refs.

• OSTI ID: 5250704
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 344; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
ALDEHYDES
CHEMICAL COMPOSITION
CHEMISTRY
COSMIC GASES
COSMOCHEMISTRY
FLUIDS
FORMALDEHYDE
GASES
GRAVITATION
HYDROCARBONS
INTERSTELLAR SPACE
MOLECULES
NITRILES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PROPIOLONITRILE
SPACE
STAR EVOLUTION