Astronomy and Astrophysics – Astrophysics
Scientific paper
Oct 1977
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1977a%26a....61..141w&link_type=abstract
Astronomy and Astrophysics, vol. 61, no. 1, Oct. 1977, p. 141-144.
Astronomy and Astrophysics
Astrophysics
4
Helium Ions, Planetary Nebulae, Radiative Recombination, Radio Spectra, Stimulated Emission, Abundance, Cations, H Lines, Line Shape, Spectral Line Width, Thermodynamic Equilibrium
Scientific paper
This note tries to show how the extent of stimulated emission in He II recombination lines can be related to that in hydrogen lines. An analysis is performed which indicates that the departure coefficients for Rydberg levels of highly excited He II ions in gaseous nebulae approximately satisfy a relationship that permits them to be readily obtained from available data for hydrogen. Non-LTE amplification factors expected for He II radio recombination lines in gaseous nebulae are estimated and found to be similar to those calculated for hydrogen lines at neighboring frequencies. An attempt is made to relate the results obtained to the detection of the He II 121-alpha radio recombination line in the spectrum of the high-excitation nebula NGC 7027. The effect of impact broadening on emergent line profiles and integrated line intensities is examined.
Walmsley Charles Malcolm
Weisheit Jon
No associations
LandOfFree
Stimulated emission of the He/+/ radio recombination lines does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Stimulated emission of the He/+/ radio recombination lines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stimulated emission of the He/+/ radio recombination lines will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-744733