Abstract
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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.