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.
Export citation and abstract BibTeX RIS