Issue |
EAS Publications Series
Volume 13, 2004
Evolution of Massive Stars, Mass Loss and Winds
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Page(s) | 317 - 337 | |
DOI | https://doi.org/10.1051/eas:2004059 | |
Published online | 15 November 2004 |
M. Heydari-Malayeri, Ph. Stee and J.-P. Zahn (eds)
EAS Publications Series, 13 (2004) 317-337
Mass-loss in central stars of planetary nebulae and in Wolf-Rayet stars
1
McGill University, Ernest Rutherford Physics Building,
3600 University St., Montréal, Québec, H3A 2T8, Canada,
2
Observatoire astronomique de Strasbourg, UMR 7550,
11 rue de l'Université, 67000 Strasbourg, France,
Corresponding authors: gyves@physics.mcgill.ca acker@newb6.u-strasbg.fr
In the present paper we review some basic facts regarding the similarities and differences between Galactic planetary nebulae (PN) and Galactic Wolf-Rayet (WR) nebulae within the scope of stellar mass-loss history and its subsequent impact on the nebular dynamics and morphology. The case of planetary nebulae with [WR] nucleus, which allows one to perform a more direct comparison with WR nebulae, is emphasized. In particular, we review selected studies on the PN NGC 40 and on the WR nebula M 1-67. We describe the apparently ubiquitous turbulent-like phenomena originating in WR/[WR] stellar atmospheres and the surrounding nebulae, and discuss the possible impact of turbulence on ejected nebula studies. The properties of turbulence observed in ejected nebulae (apparently supersonic) are at odds with the ones related to Kolmogorov's subsonic, incompressible turbulence. The large compressibility of the nebular gases and the possible multiplicity of turbulence energy sources are likely the main explanations for that difference. The Universal Multifractal approach of Lovejoy & Schertzer is presented and constitutes a physically realistic and natural way of modeling and quantifying nebular turbulence data with only three independent parameters, including the key C1 intermittence parameter.
© EAS, EDP Sciences, 2004