Electron collisional excitation of rotational transitions in CH+ and HeH+.
Abstract
Semiclassical and quantum-mechanical calculations of the cross section for electron collisional excitation of the first rotational transition of CH(+) are compared. It is found that the semiclassical approximation is sufficiently accurate at collision energies down to twice the threshold value. Collision strength is shown to be a more convenient parameter than cross section when evaluating the integral over a Maxwellian velocity distribution for the colliding electrons. It is concluded that the semiclassical results obtained for the electron collisional excitation rate of HeH(+) may also be expected to be quite accurate in the energy range relevant to studies of ionized nebulae.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 1979
- Bibcode:
- 1979A&A....73..237F
- Keywords:
-
- Electron Scattering;
- Interstellar Gas;
- Molecular Excitation;
- Molecular Ions;
- Molecular Rotation;
- Born Approximation;
- Electron Energy;
- Hydrocarbons;
- Hydrogen Ions;
- Low Temperature;
- Scattering Cross Sections;
- Astrophysics;
- Physics