CO in the southern planetary nebulae NGC 6072, NGC 6563, and IC 4406.
Abstract
Mapping observations in the CO J = 2 - 1 line are reported for three evolved southern planetary nebulas: NGC 6072, NGC 6563, and IC 4406. All three nebulas show intense and extended molecular emission. The CO spectra toward the centers of the nebulas have strongly double peaked profiles characteristic of resolved expanding envelopes. The mapping data show that the envelopes are complete, or partially complete, around the minor axis of the nebulas, but are more open along the major axis. The envelopes also appear to be fragmented. The mass of molecular gas in these objects is comparable to the mass of ionized gas, indicating that the envelopes play a major role in the evolution of the nebulas for much of their observable lifetime.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 1991
- Bibcode:
- 1991A&A...250..533C
- Keywords:
-
- Carbon Monoxide;
- Mass Distribution;
- Molecular Gases;
- Planetary Nebulae;
- Red Giant Stars;
- Line Spectra;
- Stellar Evolution;
- Stellar Mass Ejection;
- Astrophysics