Effect of scattering on instabilities in line-driven stellar winds

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Dynamic Stability, Ionization, Linearity, Radiation Distribution, Scattering, Stellar Winds, X Ray Spectra, Astronomical Models, Isotropism, Line Spectra, Stars, Transverse Acceleration, Unsteady State

Scientific paper

Line driven O-B stellar winds are unstable to perturbations of short spatial wavelength and the growth rates for such instabilities are very rapid. The nature of the nonlinear development of this instability is unknown, but might possibly be one of blobs of gas driven through ambient gas or a quasiregular train of outward moving shocks. In either case the resulting dissipation of mechanical energy might explain the observed anomalous heating n O-B stars as evidenced by their X-ray emission and high ionization state. It also might explain the observed fine structure of the absorption lines and their time variability. The driving due to the absorption of the stellar continuum flux was considered and the effects of the diffuse, scattered radiation field were neglected. It was shown that under certain special conditions the effect of scattering could reduce the instability growth rate to zero. A stability analysis that includes scattering, but that uses the more physically realistic assumption of complete redistribution instead of coherent scattering, and that includes the effects of transverse velocity gradients, which become important as the flow moves away from the stellar surface is presented. It is found that the instability is eliminated right at the base of the wind, but that as the flow moves outward the instability rate rapidly becomes equal to a substantial fraction of the calculated value, the fraction asymptotically reaching 80% at large radii. Since this still implies many e folds in a characteristic outflow time, the primary conclusion that these winds are highly unstable is unchanged.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Effect of scattering on instabilities in line-driven stellar winds does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Effect of scattering on instabilities in line-driven stellar winds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Effect of scattering on instabilities in line-driven stellar winds will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-927346

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.