Carbon chemistry in interstellar clouds toward moderately reddened stars

Journal Article · Sun May 01 04:00:00 EDT 1988 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/166336· OSTI ID:7023719

Federman, S R; Lambert, D L

New data for C2 toward X Per, HD 206267, HD 207198, and Gamma Cep, for CH and CN toward X Per, and for CO toward HD 207198 have been obtained. The column densities of CH, C2, CN, and CO toward the stars in the Cepheus OB2 association are similar to reddened directions in Perseus and in Ophiuchus, indicating a similarity in physical conditions for the foreground clouds. The available data for other directions have been analyzed and the resulting data applied to study the transition from a photochemical regime to a chemical regime. The data for N(CN), N(C2), and N(CO) have been plotted against N(CH) to elucidate the chemistry of carbon-bearing molecules more clearly. The observed trends for CN and C2 suggest a change in slope at N(CH) of roughly 5 x 10 to the 13th/sq cm. Below this value, photodestruction is predicted to dominate and the slope is determined by the photochemistry. For directions with more N(CH), a linear correlation consistent with destruction by chemical reactions is expected. 41 references.

• Research Organization: California Institute of Technology, Pasadena (USA); Texas Univ., Austin (USA)
• OSTI ID: 7023719
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 328; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CARBON
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHEMISTRY
COSMIC GASES
COSMOCHEMISTRY
ELECTROMAGNETIC RADIATION
ELEMENTS
FLUIDS
GASES
INTERSTELLAR SPACE
MOLECULES
NONMETALS
RADIATIONS
RADIOWAVE RADIATION
SPACE
TELESCOPES