A Theoretical Window into the Wind Clumping Properties of Magnetic Hot Star Winds

<p>Winds from hot, massive OB stars are driven by scattering and absorption of the stellar radiation by spectral lines. The standard line-driven wind theory of CAK predicts a smooth, steady outflow but neglects a strong radiation instability, resulting in strong shocks and a highly structured, clumped wind. Treating clumping arising from this line-deshadowing instability (LDI) is of key importance in accurately interpreting observed spectral diagnostics of massive star winds. Indeed, if not correctly accounted for, such wind clumping may lead to quite dramatic errors in inferred mass-loss properties and to correspondingly large errors in massive-star evolution predictions. So far theory and observation of the LDI have only investigated wind clumping for non-magnetic OB stars. Meanwhile, quantitative wind clumping behaviour for magnetic massive stars has not been established. However, by now there is ample evidence from spectropolarimetric surveys that a subset of OB stars in our Galaxy possesses strong, global surface magnetic fields believed to be of primordial origin. This magnetic field leads to a quenching of mass loss and can significantly alter stellar evolution, with speculations that it may even lead to formation of high stellar mass black holes. Such mass-loss rates have up until now relied on smooth wind predictions, hence do not take into account the intrinsic clumpy structures. In this contribution I present the first results of 2D numerical simulations on magnetic LDI winds that&nbsp;self-consistently predict the wind clumping phenomenon. I show the possible pathways to structure formation and discuss this in light of our recently carried out analytical perturbation analysis. Finally, I discuss the resulting wind clumping properties and the possible effects on observational diagnostics.</p>