Circumstellar Magnetic Field Diagnostics from Line Polarization

Richard Ignace (1) and Kenneth G. Gayley (2)

(1) Physics, Astronomy, and Geology, East Tennessee State University
(2) Physics and Astronomy, University of Iowa

Given that dynamically significant magnetic fields in at least some massive stars have now been measured, our contribution addresses the question, to what extent can fields be directly detected in circumstellar gas? The question speaks directly to the very interesting topic of line-driving physics coupled with magnetized plasmas, and how this coupling produces structure in the wind flow. We focus our attention on weak-field diagnostics. These come in two main types: the Hanle effect, which pertains to coherence effects for linear polarization from line scattering, and the weak longitudinal Zeeman effect, which pertains to circular polarization in lines.

Reference: to appear in the proceedings of Clumping in Hot Star Winds
Status: Conference proceedings