The detection of rotationally excited OH emission toward the probable young planetary nebula VY 2-2.
Abstract
Previous searches for rotationally excited OH have been mostly negative. However, the general situation with respect to such searches has now changed as a result of significant improvements in receiver sensitivity and the identification of new candidate objects including OH/IR stars and compact planetary nebulae. For this reason, a new investigation has been conducted. The investigation involved extensive searches for ciZcumstellar rotationally excited OH emission in transitions near 6.0 GHz and near 4.7 GHz. A primary result of the conducted searches was the detection of the 6035 MHz OH line toward the compact nebula Vyssotsky 2-2. It appears that this source is a member of the emerging class of evolved stellar objects in transition from red giant to planetary nebula. Conclusions regarding rotationally excited OH in circumstellar envelopes are discussed. For cool objects, such as OH/Miras and OH/IR stars, the lack of rotationally excited OH emission results primarily from the small population in those levels.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1985
- DOI:
- 10.1086/163364
- Bibcode:
- 1985ApJ...295..183J
- Keywords:
-
- Hydroxyl Emission;
- Interstellar Gas;
- Masers;
- Planetary Nebulae;
- Cool Stars;
- Electron Transitions;
- Hydrogen Clouds;
- Molecular Rotation;
- Stellar Envelopes;
- Astrophysics