2007ApJ...656L..21W

The first results from a near-contemporaneous optical and infrared spectroscopic observing program designed to probe the detailed density structure of classical Be circumstellar disks are presented. We report the discovery of asymmetrical infrared emission lines of He I, O I, Fe II, and the Brackett, Paschen, and Pfund series lines of H I that exhibit an opposite V/R orientation (V>R) to that observed for the optical Balmer Hα line (V<R) in the classical Be star ζ Tau. We interpret these data as evidence that the density wave that characterizes ζ Tau's disk has a significantly different average azimuthal morphology in the inner disk region as compared to the outer disk region. A follow-up multiwavelength observational campaign to trace the temporal evolution of these line profile morphologies, along with detailed theoretical modeling, is suggested to test this hypothesis.