Be discs in coplanar circular binaries: Phase-locked spectroscopic variations [SSA]

http://arxiv.org/abs/1704.06751


The first results of radiative transfer calculations on decretion discs of binary Be stars are presented. A smoothed particle hydrodynamics code computes the structure of Be discs in coplanar circular binary systems for a range of orbital and disc parameters. The resulting disc configuration is fed into a Monte Carlo code, which calculates the radiative transfer along the line of sight for various observational coordinates. Making use of the property of steady disc structure in coplanar circular binaries, various observables are computed as functions of the orbital phase. We demonstrate that binary tidal effects give rise to phase-locked variability of the violet-to-red (V/R) ratio of hydrogen emission lines. The amplitude of V/R variations is maximal for stars seen edge-on, low-viscosity discs, large orbital separations, high secondary-to-primary mass ratios. This study opens a way in constraining the parameters of binary systems that exhibit phase-locked variations.

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D. Panoglou, A. Carciofi, D. Faes, et. al.
Tue, 25 Apr 17
23/59

Comments: 5 pages, 14 figures; submitted to MNRAS