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arXiv · 1210.1861

Clumping in the inner winds of hot, massive stars from hydrodynamical line-driven instability simulations

Jon O. Sundqvist·Stanley P. Owocki
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Abstract

We investigate the effects of stellar limb-darkening and photospheric perturbations for the onset of wind structure arising from the strong, intrinsic line-deshadowing instability (LDI) of a line-driven stellar wind. A linear perturbation analysis shows that including limb-darkening reduces the stabilizing effect of the diffuse radiation, leading to a net instability growth rate even at the wind base. Numerical radiation-hydrodynamics simulations of the non-linear evolution of this instability then show that, in comparison with previous models assuming a uniformly bright star without base perturbations, wind structure now develops much closer ($r \la 1.1 R_\star$) to the photosphere. This is in much better agreement with observations of O-type stars, which typically indicate the presence of strong clumping quite near the wind base.

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Jon O. Sundqvist, Stanley P. Owocki. 2012-10-05. Clumping in the inner winds of hot, massive stars from hydrodynamical line-driven instability simulations. https://doi.org/10.1093/mnras%2Fsts165

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