Radiative excitation and the intensities of radio recombination lines.
Abstract
The present investigation of the influence of the absorption of stellar Lyman line photons on the population of highly excited states of H in H II regions indicates that, for hot ionizing stars with an effective temperature of more than 50,000 K, radiative excitation is unimportant. Radiative excitation is more efficient for cooler stars, of less than 40,000 K, and if the Lyman jump is sufficiently sharp, it may become an important process at stellar temperatures of less than 35,000 K. It is also found that, in nebulae excited by stars of spectral type later than about O6, the contribution of radiative excitation to radio recombination line intensities is not negligible.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1983
- Bibcode:
- 1983A&A...121L..19H
- Keywords:
-
- Hydrogen Recombinations;
- Interstellar Masers;
- Lyman Spectra;
- Radio Spectra;
- Stellar Spectra;
- Atmospheric Models;
- Atomic Excitations;
- Balmer Series;
- H Ii Regions;
- Hot Stars;
- Opacity;
- Astrophysics