Previous abstract Next abstract

Session 26 - Proto Stars to Supernovae.
Oral session, Monday, June 08
Sierra,

[26.03] Line-Driven Ablation and Wind Tilting by External Irradiation

K. Gayley (University of Iowa), S. Owocki (Bartol Research Inst.), S. Cranmer (Harvard Smithsonian)

Sobolev opacity in a hot-star wind preferentially scatters photons that are incident along the direction of steepest velocity gradient. This non-isotropic response can rotate the force vector relative to the direction of net radiative flux, in a manner analogous to the way a non-isotropic sail and keel can allow a boat to sail upwind. For hot star binaries, the curious feedback between the radiative forces and the flows they drive allows for counter-intuitive self-consistent solutions. For example, we show that illumination that is purely external to a reflecting radiative-equilibrium atmosphere can ablate a highly tilted and fast wind, loosely reminiscent of ``tacking'' in the sailing analogy. The conclusion is that whenever the radiation source geometry is complicated, the non-isotropic nature of Sobolev opacity must be carefully accounted for to obtain even a qualitative understanding of the atmospheric response. Thus CAK theory continues to reveal new surprises even in its most basic formulation.


The author(s) of this abstract have provided an email address for comments about the abstract: kenneth-gayley@uiowa.edu

Program listing for Monday