The complex motions of the neutral and ionized gas within the Dumb-bell Nebula (NGC 6835) - II.
Abstract
An electronographic insect-eye Fabry-Perot spectrograph has been used to obtain profiles of the forbidden O III, forbidden N II, and forbidden O I emission lines at many positions over the Dumbbell Nebula. Narrow forbidden O I and forbidden N II lines are observed from the central areas. These are split into two distinct components separated by around 66 km/s. However, broader forbidden O III lines, though often doubled by only about 30 km/s, are observed. A cylindrical (or ellipsoidal) shell model of the nebula, expanding radially with respect to its axis rather than the central star, explains many of the observations. Very unusual motions are observed near the exciting star
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 1978
- DOI:
- 10.1093/mnras/182.1.13
- Bibcode:
- 1978MNRAS.182...13G
- Keywords:
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- Interstellar Gas;
- Neutral Gases;
- Planetary Nebulae;
- Plasma Physics;
- Rarefied Gas Dynamics;
- Astronomical Models;
- Atomic Excitations;
- Nitrogen;
- Oxygen Spectra;
- Astrophysics;
- Forbidden Lines:Planetary Nebulae;
- Planetary Nebulae: Internal Motions