A Mechanism for the Production of Jets and Ansae in Planetary Nebulae
Abstract
Many elliptical planetary nebulae (PNs) exhibit pairs of small, low-ionization structures called "jets" and ansae, which are characterized by their equal and opposite displacements (0.01--0.03 pc) and redshifts (50 km s-1) from the nucleus along the nebular symmetry axis. Here we propose that jets and ansae can quite easily develop prior to the onset of the fast wind during the proto-PN phase. Using nominal descriptors, which include an accelerating fast wind and a toroidal slow-wind mass-loss geometry to form elliptical PNs, we find a wide range of conditions under which jets and ansae can develop. We show that the expected sizes, velocities, and ionization of these microstructures conform quite nicely to observations.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1996
- DOI:
- 10.1086/310322
- Bibcode:
- 1996ApJ...471L..53F
- Keywords:
-
- STARS: CIRCUMSTELLAR MATTER;
- ISM: JETS AND OUTFLOWS;
- ISM: PLANETARY NEBULAE: GENERAL