Charge transfer of C/+/ and S/+/ in diffuse nebulae
Abstract
The rate coefficient for the charge transfer reaction C+(2P0) + H yields C(3P) + H(+) is calculated. At low energy, the reaction probably proceeds most rapidly by a weak spin orbit coupling of the 3Sigma(-) and 3Sigma(+) molecular states of CH(+) and it can be adequately treated using the distorted wave approximation. The derived rate coefficient at a temperature of 10,000 K is 1.4 x 10 to the -17th cu cm/s. An estimate of the rate coefficient for the reaction S+(4S0) + H yields S(3P) + H(+) is made; the reaction can proceed by a mechanism similar to the C(+)-H process. By scaling the carbon result, an approximate upper limit of 3 x 10 to the -15th cu cm/s is obtained for the rate coefficient at 10,000 K achievable only if the SH(+) potential energy curves are favorably located. The results differ by orders of magnitude from the empirical rate coefficients derived from a study of the neutral carbon and sulfur observed in diffuse nebulae.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1980
- Bibcode:
- 1980A&A....85..144B
- Keywords:
-
- Carbon;
- Charge Transfer;
- Chemical Reactions;
- Nebulae;
- Sulfur;
- Hydrogen Clouds;
- Molecular Collisions;
- Positive Ions;
- Reaction Kinetics;
- Astrophysics