Multi-dimensional Modeling of Massive Binary Interaction in Eta Carinae

We summarize recent efforts from our group to constrain the nature of both stars in the Eta Carinae binary system and its orbital parameters by studying the influence of the companion star on the spectrum of the primary star. We find that the cavity in the dense wind of the primary star strongly affects multi-wavelength diagnostics such as the ultraviolet spectrum, the optical hydrogen lines, and the shape of the near-infrared continuum region. These diagnostics have been previously interpreted as requiring a latitude-dependent wind generated by a fast-rotating primary star, but the effects of the companion on them provide tenuous evidence that the primary star is a rapid rotator.