Astronomy and Astrophysics – Astrophysics
Scientific paper
Jul 1990
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990a%26a...233..540t&link_type=abstract
Astronomy and Astrophysics (ISSN 0004-6361), vol. 233, no. 2, July 1990, p. 540-552.
Astronomy and Astrophysics
Astrophysics
72
Abundance, Gas Ionization, Halos, Planetary Nebulae, Ultraviolet Spectra, Chemical Composition, Iue, Line Spectra
Scientific paper
New observations in the 3400 - 7500 A range are presented for NGC 2242 and NGC 4361, and new IUE observations are presented for NGC 2242. The physical conditions and chemical composition for these nebulae are derived. The ionization structure of both PN are very similar, the PN are very optically thin to Lyman continuum photons, and more than 90 percent of helium is in the twice-ionized stage. Their chemical abundances and distances to the galactic plane correspond to those of population II objects. Both show C/O ratios larger than unity. The carbon recombination lines in NGC 4361 are very strong and seem to indicate that the C/O ratio is not homogeneous within the nebula; an inhomogeneous model with C/O rich regions is constructed which is in good agreement with the observed data. A discussion of the chemical composition of the seven known halo PN is given.
Peimbert Manuel
Peña Manuel
Torres-Peimbert Silvia
No associations
LandOfFree
Planetary nebulae with a high degree of ionization - NGC 2242 and NGC 4361 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 Planetary nebulae with a high degree of ionization - NGC 2242 and NGC 4361, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Planetary nebulae with a high degree of ionization - NGC 2242 and NGC 4361 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1091403