Ion-molecule calculation of the abundance ratio of CCD to CCH in dense interstellar clouds

Journal Article · Wed Dec 31 23:00:00 EST 1986 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/164880· OSTI ID:6398668

Herbst, E; Adams, N G; Smith, D; Defrees, D J

Laboratory measurements and calculations have been performed to determine the abundance ratio of the deuterated ethynyl radical (CCD) to the normal radical (CCH) which can be achieved in dense interstellar clouds via isotopic fractionation in the C/sub 2/H/sub 2/(+) (HD)=C/sub 2/HD(+)(H/sub 2/) system of reactions. According to this limited treatment, the CCD/CCH abundance ratio which can be attained is in the range 0.02-0.03 for the Orion molecular cloud and 0.0l-0.02 for TMC-1. These ranges of numbers are in reasonable agreement with the observed values in Orion and TMC-1. However, the analysis of the CCD/CCH abundance ratio is complicated via the presence of competing fractionation mechanisms, especially in the low-temperature source TMC-1. 28 references.

• Research Organization: Duke Univ., Durham, NC; Birmingham Univ., England; Molecular Research Institute, Palo Alto, CA
• OSTI ID: 6398668
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 312; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CHARGED PARTICLES
CHEMICAL COMPOSITION
CHEMISTRY
COSMIC GASES
COSMOCHEMISTRY
FLUIDS
GASES
HYDROCARBONS
HYDROGEN ISOTOPES
INTERSTELLAR SPACE
IONS
ISOTOPES
KINETICS
MOLECULAR IONS
ORGANIC COMPOUNDS
RADICALS
REACTION KINETICS
SPACE