Electron densities for six planetary nebulae and HM SGE derived fromthe CIII lambda 1907/1909 ratio.
Abstract
Electron densities for IC 418, NGC 6572, IC 1297, NGC 3242, NGC 6818, NYC 3211, and HM Sagittae derived from high-dispersion IUE C III] spectrograms are consistently higher than those derived from either surface brightness measurements or forbidden line intensity ratios in the visible. The nebulae were selected for a range of excitation classes from 3 to 9. Line splitting due to expansion velocities is observed for three objects. The great width of the λ1909 C III] line in MM Sagittae suggests large expansion velocities.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1980
- DOI:
- 10.1086/158383
- Bibcode:
- 1980ApJ...241..725F
- Keywords:
-
- Carbon;
- Electron Density (Concentration);
- Infrared Spectra;
- Planetary Nebulae;
- Protoplanets;
- Forbidden Transitions;
- Iue;
- Radial Velocity;
- Spectral Line Width;
- Spectrograms;
- Astrophysics