Abstract
view Abstract Citations (52) References (49) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Infrared-Line Emission from Planetary Nebulae Delmer, Thomas N. ; Gould, Robert J. ; Ramsay, William Abstract The general physical processes are considered which determine the intensities of infrared emission lines resulting from magnetic dipole transitions between fine-structure levels in certain abundant ions. Ionization equilibrium and fine-structure level population are discussed. Radiative recombination is treated in some detail in an appendix where general results are given for averaged recombination Gaunt factors and for approximate intensities of helium recombination line intensities. By means of the quantum defect method, some important collision strengths for fine structure transitions are calculated. On the basis of optical data, estimates are given of the expected infrared-line intensities from nine bright planetary nebulae. There are a number of lines from these planetaries which should have intensities in the range of 10- -16 W/cm2 and which should be observable from below the atmosphere through the 8-14- and 17-24- windows. Improved estimates are given of the expected thermal bremsstrahlung radio emission from these nebulae, with the assumption that they are optically thin to radio radiation; comparison with radio observations indicates generally satisfactory agreement with these calculations of radio emission. Publication: The Astrophysical Journal Pub Date: September 1967 DOI: 10.1086/149281 Bibcode: 1967ApJ...149..495D full text sources ADS | data products SIMBAD (9)
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