Galactic abundances of neon, argon, and chlorine derived from planetary nebulae

Journal Article · Sun Oct 15 04:00:00 EDT 1978 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/156513· OSTI ID:6535685

Kaler, J B

Mean neon and argon to oxygen ratios are found from planetary nebula to be Ne/O=0.225 +- 0.01 and Ar/O=7.0 +- 0.5 x 10/sup -3/. The mean Arr/Cl ratio is 21.3 +- 2.3, which results in Cl/O=3.3 +- 0.5 x 10/sup -4/. The errors quoted are internal, and arise mostly from observational scatter. The accuracy of these nebular abundances is now limited by the calculated atomic data. The Ne/O ratio is probably the most accurate, and the Cl/Ar, Cl/O the least. The external error imposed by the Cl cross sections is probably less than +- 25%. If the three extreme halo planetaries are excluded, these ratios are constant among nebulae within the observational errors, so that the mean values have galactic significance. No variation in Ne/O with galactic position is seen, except that the halo planetary Ha 4-1 is a factor of 10 deficient in Ne compared with O. Comparison with other observations shows that these planetary abundance ratios are essentially solar. The observed ratios are in general agreement with the predictions of explosive nucleosynthesis; however, the measured Cl is a factor of 3-5 more abundant than the predicted values. The neon, argon, and chlorine abundances found in planetaries are apparently typical of the interstellar medium out of which the stars were formed. Since solar values for these elements are apparently not as well determined, the abundances presented here could be used to improve the compilations of ''solar'' or ''local galactic'' abundances.

• Research Organization: University of Illinois Observatory
• OSTI ID: 6535685
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 225:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
ARGON
CHEMICAL COMPOSITION
CHEMISTRY
CHLORINE
COSMOCHEMISTRY
ELEMENTS
GALACTIC EVOLUTION
GALAXIES
HALOGENS
IONIZATION
MILKY WAY
NEBULAE
NEON
NONMETALS
NUCLEOSYNTHESIS
PLANETARY NEBULAE
RARE GASES