ON THE WIND GEOMETRY OF THE WOLF-RAYET STAR EZ CANIS MAJORIS

Recent models of Wolf-Rayet star winds have been tailored to EZ CMa, and make predictions of the envelope structure and location of line-emitting regions. We discuss how the wind structure of EZ CMa can be probed observationally through electron distribution integrals as measured by spectropolarimetry, and then present, analyze, and interpret a time-dependent spectropolarimetric data set of EZ CMa. The observations further our view of an electron-scattering wind that is axisymmetric, rotating, and expanding, with a variable mass-loss rate being responsible for the quasi-periodic polarimetric variability. We demonstrate that the emission lines of EZ CMa are partially polarized, indicating that line photons are electron-scattered in the wind. The polarization in N V lambda-4945 and N IV lambda-4058 is observed to be larger than that of He II lambda-4686 and He I lambda-5876, as expected from ionization stratification.