Forbidden O III and N III far-infrared line emission in dusty H II blisters
P. A. Aannestad, R. J. Emery;
AaA, 1985, 145, 347
ABSTRACT:The FIR line emission spectrum of an H II region with an exponential density gradient (i.e.,
the blister characterized by Icke et al., 1980) is determined on the basis
of model simulations, applying the ionizing spectrum of the 50,000 K
model stellar atmosphere of Kurucz (1979) and taking He ionization,
charge-exchange reactions, and the N and O dielectronic recombination rates of Shull
and Steenburg (1982) and Nussbaumer and Storey (1983) into account.
The
results are presented graphically, including the approximate intensities of
the forbidden lines of O III at 52 and 88 microns and of N III at 57 microns at
viewing angles 0-90 deg.
Although the intensities vary closely with the
free-free radio emission, the electron density calculated from the O III line
ratio is up to three times higher than the radio rms density.
KEYWORDS: emission spectra, forbidden transitions, interstellar gas, ionizing radiation, nitrogen ions, oxygen spectra, cosmic dust, far infrared radiation, gas ionization, h ii regions, line spectra, particle density (concentration)
PERSOKEY:REGION HII, ,
CODE: aannestad85