Other
Scientific paper
Jan 1978
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1978apj...219..565s&link_type=abstract
Astrophysical Journal, Part 1, vol. 219, Jan. 15, 1978, p. 565-574.
Other
64
Astronomical Models, Line Spectra, Photoionization, Planetary Nebulae, Forbidden Transitions, Gas Ionization, Lyman Spectra, Oxygen Spectra, Recombination Coefficient, Red Shift, Stellar Spectra, Transition Probabilities, Ultraviolet Radiation
Scientific paper
The emission-line spectrum of NGC 7027 is analyzed with the aid of detailed models based on photoionization equilibrium theory. The models explain the temperature and the fractional abundances of most ions but seriously underestimate the abundances of O II and other ions in the H II - H I transition zone. Multidensity geometries, modifications of the stellar continuum, and internal reddening of the ionizing radiation fail to resolve this difficulty. Dynamical processes, in particular evaporating globules, are a promising solution. Chemical abundances are derived for He, C, N, O, Ne, Ar, and Fe. A C/O ratio about 6 times larger than solar is indicated by optical recombination lines, forbidden lines, and ultraviolet lines. N/O is more than twice the solar value. Fe/O is a factor of 25 lower than solar; it is shown that condensation of iron into grains does not conflict with the absence of internal reddening in NGC 7027.
No associations
LandOfFree
Ionization structure and composition of the planetary nebula NGC 7027 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 Ionization structure and composition of the planetary nebula NGC 7027, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ionization structure and composition of the planetary nebula NGC 7027 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-943551