Year: 2004
Type: article
Abstract: Ambient interstellar material may become entrained in outflows from massive stars as a result of shear flow instabilities. We study the linear theory of the Kelvin-Helmholtz instability, the simplest example of shear flow instability, in a partially ionized medium. We model the interaction as a two-fluid system (charged and neutral) in a planar geometry. Our principal result is that for much of the relevant parameter space, neutrals and ions are sufficiently decoupled that the neutrals are unstable while the ions are held in place by the magnetic field. Thus, we predict that there should be a detectably narrower line profile in ionized species tracing the outflow compared with neutral species, since ionized species are not participating in the turbulent interface with the ambient ISM. Since the magnetic field is frozen to the plasma, it is not tangled by the turbulence in the boundary layer.
Source: The Astrophysical Journal
DOI: 10.1086/392500
Authors: C. Watson, E. G. Zweibel, F. Heitsch, E. Churchwell
Institution: University of Wisconsin–Madison
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2057580854