Published online by Cambridge University Press: 25 May 2016
The general properties of elliptical planetary nebulae have been very successfully explained by a class of hydrodynamic models known as interacting stellar winds (ISW). PNs also contain a variety of microstructures (Anase,“FLIERs”) whose origins have remained puzzling. We (Frank, Balick, & Livio 1996) have shown that such flows will naturally occur in the ISW model in momentum-conserving PPN bubbles, and that they can naturally account for the formation of jets and ansae in a way consistent with extant observations.