Astronomy and Astrophysics – Astrophysics
Scientific paper
Nov 1990
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990a%26a...239..287c&link_type=abstract
Astronomy and Astrophysics (ISSN 0004-6361), vol. 239, no. 1-2, Nov. 1990, p. 287-300.
Astronomy and Astrophysics
Astrophysics
10
Electron Recombination, H Ii Regions, Interstellar Matter, Line Spectra, Nonequilibrium Thermodynamics, Radio Spectra, Carbon, Hydrogen, Lyman Spectra, Molecular Spectra, Stimulated Emission
Scientific paper
Radio recombination lines have been observed toward 30 H II regions with the Arecibo 305 m telescope at 1.6 GHz. The H 159 alpha line was detected in 22 of the sources, including five new detections. The beta/alpha ratio is measured in 13 sources in order to study non-LTE effects in radio recombination lines. Two sources show large beta/alpha ratios suggesting stimulated emission illuminated by a background radiation field. Three sources show low beta/alpha ratio with evidence of pressure broadening present. In other sources, where pressure broadening is not observed, non-LTE effects are responsible for the low beta/alpha ratios, and even clumping in these H II regions cannot inhibit the non-LTE effects. It is suggested that the non-LTE effects could be consistent with the Lyman line pumping model.
Cersosimo Juan Carlos
Magnani Loris
No associations
LandOfFree
Non-LTE effects in radio recombination lines from H II regions at 18 CM 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 Non-LTE effects in radio recombination lines from H II regions at 18 CM, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-LTE effects in radio recombination lines from H II regions at 18 CM will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-838733