Radiation Gasdynamics of Planetary Nebulae: From Diversity to Unity

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Session 2 -- Planetary Nebula and Supernova Remnants
Display presentation, Monday, 9:20-6:30, Pauley Room

[2.08] Radiation Gasdynamics of Planetary Nebulae: From Diversity to Unity

A. Frank (UM)

I present the results of 1 and {2-D} numerical radiation-gasdynamical simulations of Planetary Nebulae (PNe) evolution. The models are based on the Interacting Stellar Winds (ISW) scenario and include radiation transfer, ionization, ionization heating, forbidden, permitted, and other collisional cooling processes in an explicit time-dependent treatment.

In the {1-D} spherically symmetric models the interaction of three (fast, super, and AGB) winds are simulated. The dynamics of the {1-D} models are complex but regular with gasdynamic and ionization discontinuities interacting nonlinearly. Because of this radiation-gasdynamic interaction the models pass through four distinct evolutionary phases. When synthetic observations are made from the model forbidden and permitted line emissivities each evolutionary phase is seen to display distinct morphological, kinematic, and ionization structure characteristics. The general features of synthetic observations match well with those seen in real spherical PNe. In particular the models demonstrate that the diverse kinematical and multi-shell patterns observed in spherical PNe (taken as a class of objects) can be seen as the radiation-gasdynamic consequences of a single evolutionary (ISW) scenario.

In the {2-D} axi-symmetric models we generalize the ISW scenario to include higher densities along the equator in the slow wind. The simulations demonstrate that elliptical and bipolar morphologies develop naturally from the gasdynamic interaction of a fast wind and a toriodial slow wind. Synthetic observations of integrated intensities show that most observed PNe morphologies can be recovered by considering inclination effects on the projected nebular image. Synthetic long slit spectrum images demonstrate that the absolute velocities and kinematic patterns observed in real aspherical PNe are reproduced in the models

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