From the Owl to the Eskimo: the Radiation-Gasdynamics of Planetary   Nebulae IV
  We present the results of two-dimensional radiation-gasdynamic simulations of aspherical Planetary Nebulae (PNe) evolution. These simulations were constructed using the Generalized Interacting Stellar Winds (GISW) scenario of Balick (1987) where a fast, tenuous wind from the central star expands into a toroidal, slow, dense wind. We demonstrate that the GISW model can produce a wide range of aspherical flow patterns.   We have constructed self-consistent synthetic observations of the models from forbidden line emissivities used in the energy loss term. We present integrated intensity and long-slit spectrum, (Position-Velocity) maps of the models projected at different angles on the sky. These synthetic observations are compared with real intensity and Position-Velocity maps of PNe. We find that there is a very good match between the synthetic and real observations in terms of morphologies, kinematics, and physical conditions.   From the results of these simulations we conclude that the GISW scenario can account for most, if not all, PNe morphologies, thus confirming Balick's (1987) conjecture. 
Adam Frank and Garrelt Mellema