Diffuse Interstellar Clouds as a Chemical Laboratory: The Chemistry of Diatomic Carbon Species
Abstract
The chemistry of C2, CH, and CO in diffuse interstellar clouds is analyzed and compared to absorption line measurements toward background stars. Analytical expressions in terms of column densities are derived for the rate equations. The results indicate that in clouds with 4 mag of visual extinction, the abundance of C+ has to decrease by a factor of about 15 from the value traditionally used for clouds with 1 mag of extinction. The rate coefficients for the reactions C+ + CH - C2+ + H and C+ + H2 - CH2+ + h-nu need to be reduced from previous estimates. Chemical arguments are presented for the revised rate coefficients.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1989
- DOI:
- 10.1086/167187
- Bibcode:
- 1989ApJ...338..140F
- Keywords:
-
- Carbon Compounds;
- Diatomic Molecules;
- Interstellar Chemistry;
- Molecular Clouds;
- Absorption Spectra;
- Molecular Diffusion;
- Photochemical Reactions;
- Astrophysics;
- INTERSTELLAR: ABUNDANCES;
- INTERSTELLAR: MOLECULES;
- MOLECULAR PROCESSES