On the early evolution of aspherical Wolf-Rayet bubbles

Details On the early evolution of aspherical Wolf-Rayet bubbles On the early evolution of aspherical Wolf-Rayet bubbles

Feb 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997mnras.285..387b&link_type=abstract

Monthly Notices of the Royal Astronomical Society, Volume 285, Issue 2, pp. 387-393.

Astronomy and Astrophysics

Astronomy

14

Hydrodynamics, Stars: Wolf-Rayet, Ism: Bubbles, Ism: Individual: Ngc 6888.

Scientific paper

We present several models of the evolution of young Wolf-Rayet (WR) ring nebulae. We focus on the transient but non-negligible phase during which the stellar wind is accelerated, from a velocity of about 10 km s^-1 in the red supergiant (RSG) stage to velocities of the order of 2000 km s^-1, typical of WR winds. The WR wind interacts with the free RSG wind and sweeps up an accelerating shell. This shell experiences a strong Rayleigh-Taylor instability and fragments, producing dense knots and filaments. Note that this happens before it interacts with the shell swept up by the RSG wind. We also assume an anisotropic RSG wind. Initially the outer shock of the nebula is isothermal, given its low velocity and the high density of the RSG wind close to the star. Later on the shock becomes adiabatic and the transition to the fast adiabatic regime occurs earlier along the polar direction, where the density is lower. In this phase the post-shock gas of the adiabatic shock is hot enough to emit soft X-rays. We compare our results with the well studied WR ring nebula NGC 6888. It shows an ellipsoidal, filamentary shell at optical wavelengths, while in the X-ray two lobes are present in opposite zones along the major axis. We find that our simple model may qualitatively explain these features. Our hypotheses are not specific for NGC 6888 and we expect that the `two-lobe' X-ray morphology is a common attribute of young ring nebulae.

Affiliated with

Also associated with

No associations

Rating

On the early evolution of aspherical Wolf-Rayet bubbles 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 On the early evolution of aspherical Wolf-Rayet bubbles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the early evolution of aspherical Wolf-Rayet bubbles will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1605423