Infrared line measurements and the abundance of sulfur in planetary nebulae.
Abstract
Ionic abundances of S(+), S(++), and S(+3) relative to hydrogen are determined for 12 planetary nebulae from observations of the S II forbidden lines at 6716 and 6731 A, the S III forbidden line at 9531 A, the S IV forbidden line at 10.5 microns, and P delta 10049 A. The derived total abundances are insensitive to electron density and electron temperature and are found to vary by no more than 30% in the sample; unlike previous determinations, there is no correlation of the abundance with the degree of ionization. The mean elemental abundance for these objects is S/H = 2.1 plus or minus 0.6 x 10 to the -5th, which is, within the measurement errors, the same as the solar value and the abundance in the present interstellar medium as represented by the H II regions K3-50 and Orion.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1980
- DOI:
- 10.1086/157892
- Bibcode:
- 1980ApJ...237..486D
- Keywords:
-
- Abundance;
- Infrared Spectroscopy;
- Planetary Nebulae;
- Sulfur;
- Electron Density (Concentration);
- Electron Energy;
- Forbidden Transitions;
- H Ii Regions;
- Interstellar Matter;
- Line Spectra;
- Astrophysics