Far-infrared /O III/ and /N III/ line emission from galactic H II regions and planetary nebulae

Abstract

view Abstract Citations (32) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Far-infrared (O III) and (N III) line emission from galactic H II regions and planetary nebulae. Watson, D. M. ; Storey, J. W. V. ; Townes, C. H. ; Haller, E. E. Abstract Measurements of 0++ and N++ fine structure lines in several galactic H II regions and planetary nebulae are reported. Emission from [O III] 51.8 μm was detected in the diffuse nebulae Ml7, W43, W49, W5l, and NGC 7538, and marginally in the planetary nebula NGC 6543, with upper limits obtained for the compact H II region DR 21 and the planetary nebulae M57 (NGC 6720) and NGC 7027. The [N III] 57.3 μm line was detected in Ml7 and W5l. Preliminary maps were made of Ml7 and W51 in the [O III] 51.8 μm line, and of Ml7 in the [N III] 57.3 μm line. We combine the present results with previous [O III] 88.4 m data to obtain electron densities in Ml7, W49, W5l, and NGC 7538, and N++/O++ abundance ratios in Ml7 and W5l. The implications of these measurements with regard to the ionization conditions in the nebulae are discussed. Publication: The Astrophysical Journal Pub Date: November 1981 DOI: 10.1086/159407 Bibcode: 1981ApJ...250..605W Keywords: H Ii Regions; Infrared Astronomy; Nitrogen Ions; Oxygen Spectra; Planetary Nebulae; Spectral Line Width; Abundance; Electron Density Profiles; Emission Spectra; Far Infrared Radiation; Fine Structure; Astrophysics full text sources ADS | data products SIMBAD (3)