Toward Mapping the Detailed Density Structure of Classical Be Circumstellar Disks

Abstract

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 which exhibit an opposite V/R orientation (V $>$ R) to that observed for the optical Balmer H$\alpha$ line (V $<$ R) in the classical Be star $\zeta$ Tau. We interpret these data as evidence that the density wave which characterizes $\zeta$ 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 multi-wavelength observational campaign to trace the temporal evolution of these line profile morphologies, along with detailed theoretical modeling, is suggested to test this hypothesis.

13 pages, accepted by ApJL

References in corpus (3)

• NLTE Monte Carlo Radiative Transfer: I. The Thermal Properties of Keplerian Disks around Classical Be Stars
• The Role of Evolutionary Age and Metallicity in the Formation of Classical Be Circumstellar Disks I. New Candidate Be Stars in the LMC, SMC, and Milky Way
• Properties of the $\delta$ Scorpii Circumstellar Disk from Continuum Modeling

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• High-resolution, H band Spectroscopy of Be Stars with SDSS-III/APOGEE: I. New Be Stars, Line Identifications, and Line Profiles
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• A New Diagnostic of the Radial Density Structure of Be Disks
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• New Oe stars in LAMOST DR5
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