Oscillator strengths for O III and the Bowen fluorescent mechanism
Abstract
Transition probabilities and relative intensities are calculated for transitions between O III triplets excited by the Bowen fluorescence mechanism, which have been observed in the optical spectra of nebulae. A frozen cores approximation is used to obtain wavelengths and oscillator strengths for the dipole transitions and the probabilities of a Bowen cascade and the various transitions within the cascade following excitation of the 2p 3d 3P(0)2 state of O III. Intensities of the O III lines and multiples calculated relative to those for the He II line at 4686 A and cascade proportions are shown to agree with the values observed in the optical and UV of the planetary nebula NGC 7662. The observed relative intensities of the O III lines, in the solar spectrum at wavelengths of 644 and 374 A, however, are found to be inconsistent with the Bowen mechanism.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 1980
- DOI:
- 10.1093/mnras/193.3.617
- Bibcode:
- 1980MNRAS.193..617S
- Keywords:
-
- Atomic Excitations;
- Electron Transitions;
- Fluorescence;
- Oxygen Ions;
- Oxygen Spectra;
- Ultraviolet Astronomy;
- Cascades;
- Line Spectra;
- Planetary Nebulae;
- Transition Probabilities;
- Astrophysics