The Dynamical Evolution of Planetary Nebulae After the Fast Wind

Abstract

In this paper we explore the dynamics of ionization bounded planetary nebulae after the termination of the fast stellar wind. When the stellar wind becomes negligible, the hot, shocked bubble depressurizes and the thermal pressure of the photoionized region, at the inner edge of the swept-up shell, becomes dominant. At this stage the shell tends to fragment creating clumps with comet-like tails and long, photoionized trails in between, while the photoionized material expands back towards the central stars as a rarefaction wave. Once that the photoionized gas fills the inner cavity, it develops a kinematical pattern of increasing velocity from the center outwards with a typical range of velociti es starting from the systemic velocity to 50 Km/s at the edges. The Helix nebula is a clear example of a planetary nebula at this late evolutionary stage.

10 pages, 3 figures, accepted by ApJ Letters

Cited by in corpus (6)

• Determination of the Physical Conditions of the Knots in the Helix Nebula from Optical and Infrared Observations
• VLT / Infrared Integral Field Spectrometer Observations of Molecular Hydrogen Lines in the Knots in the Planetary Nebula NGC 7293 (the Helix Nebula)
• The Acceleration of the Nebular Shells in Planetary Nebulae in the Milky Way Bulge
• The planetary nebula NGC 1360, a test case of magnetic collimation and evolution after the fast wind
• Optical line profiles of the Helix planetary nebula (NGC 7293) to large radii
• The gas turbulence in planetary nebulae: quantification and multi-D maps from long-slit, wide-spectral range echellogram