Far-infrared (OIII) and (NIII) line emission from galactic H II regions and planetary nebulae

Journal Article · Sun Nov 15 00:00:00 EST 1981 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159407· OSTI ID:5655375

Watson, D M; Storey, J W.V.; Townes, C H; Haller, E E

Measurements of O/sup + +/ and N/sup + +/ fine structure lines in several galactic H II regions and planetary nebulae are reported. Emission from (OIII) 51.8 ..mu..m was detected in the diffuse nebulae M17, W43, W49, W51, and NGC 7538, and marginally in the planetary nebulae 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 ..mu..m line was detected in M17 and W51. Preliminary maps were made of M17 and W51 in the (OIII) line, and of M17 in the (N III) 57.3 ..mu..m line. We combine the present results with previous (OIII)88.4 ..mu..m data to obtain electron densities in M17, W49, W51, and NGC 7538, and N/sup + +//O/sup + +/ abundance ratios in M17 and W51. The implications of these measurements with regard to the ionization conditions in the nebulae are discussed.

• Research Organization: Department of Physics, University of California, Berkely
• OSTI ID: 5655375
• Journal Information: Astrophys. J.; (United States), Vol. 250:2
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
H2 REGIONS
CHEMICAL COMPOSITION
INFRARED SPECTRA
PLANETARY NEBULAE
ABUNDANCE
ELECTRON DENSITY
EMISSION
FAR INFRARED RADIATION
FINE STRUCTURE
GALAXIES
IONIZATION
NITROGEN IONS
OXYGEN IONS
CHARGED PARTICLES
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
INFRARED RADIATION
IONS
NEBULAE
RADIATIONS
SPECTRA
640105* - Astrophysics & Cosmology- Galaxies