On the stability of radiation-pressure-dominated cavities

Details On the stability of radiation-pressure-dominated cavities On the stability of radiation-pressure-dominated cavities

2011-11-23

arxiv.org/abs/1111.5625v1

Astronomy & Astrophysics, Volume 537, id.A122 (2012)

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

14 pages, 8 figures, accepted at A&A

Scientific paper

10.1051/0004-6361/201117808

Context: When massive stars exert a radiation pressure onto their environment that is higher than their gravitational attraction, they launch a radiation-pressure-driven outflow. It has been claimed that a radiative Rayleigh-Taylor instability should lead to the collapse of the outflow cavity and foster the growth of massive stars. Aims: We investigate the stability of idealized radiation-pressure-dominated cavities, focusing on its dependence on the radiation transport approach for the stellar radiation feedback. Methods: We compare two different methods for stellar radiation feedback: gray flux-limited diffusion (FLD) and ray-tracing (RT). We also derive simple analytical models to support our findings. Results: Only the FLD cases lead to prominent instability in the cavity shell. The RT cases do not show such instability. The gray FLD method underestimates the opacity at the location of the cavity shell and leads to extended epochs of marginal Eddington equilibrium in the cavity shell, making them prone to the radiative Rayleigh-Taylor instability. In the RT cases, the radiation pressure exceeds gravity by 1-2 orders of magnitude. The radiative Rayleigh-Taylor instability is then consequently suppressed. Conclusions: Treating the stellar irradiation in the gray FLD approximation underestimates the radiative forces acting on the cavity shell. This can lead artificially to situations that are affected by the radiative Rayleigh-Taylor instability. The proper treatment of direct stellar irradiation by massive stars is crucial for the stability of radiation-pressure-dominated cavities.

Affiliated with

Also associated with

No associations

Rating

On the stability of radiation-pressure-dominated cavities 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 stability of radiation-pressure-dominated cavities, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the stability of radiation-pressure-dominated cavities will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-155869