On the Intrinsic Continuum Linear Polarization of Classical Be Stars during Disk Growth and Dissipation

Abstract

We investigate the intrinsic continuum linear polarization from axisymmetric density distributions of gas surrounding classical Be stars during the formation and dissipation of their circumstellar disks. We implement a Monte Carlo calculation of the Stokes parameters with the use of the non-LTE radiative transfer code of Sigut & Jones (2007) to reproduce the continuous polarimetric spectra of classical Be stars. The scattering of light in the nonspherical circumstellar envelopes of classical Be stars produces a distinct polarization signature that can be used to study the physical nature of the scattering environment. In this paper, we highlight the utility of polarimetric measurements as important diagnostics in the modeling of these systems. We illustrate the effects of using self-consistent calculation of the thermal structure of the circumstellar gas on the characteristic wavelength-dependence of the polarization spectrum. In showing that the principal features of the polarization spectrum originate from different parts of the disk, we emphasize the capability of polarimetric observations to trace the evolution of the disk on critical scales. We produce models that approximate the disk formation and dissipation periods and illustrate how the polarimetric properties of these systems can have a pivotal role in determining the mechanism for mass decretion from the central star.

Accepted to ApJ on January 15, 2013

References in corpus (6)

• The Thermal Structure of the Circumstellar Disk Surrounding the Classical Be Star gamma Cassiopeia
• Non-LTE Monte Carlo Radiative Transfer: II. Non-Isothermal Solutions for Viscous Keplerian Disks
• The remarkable light and colour variability of Small Magellanic Cloud Be stars
• Constraining the Physical Parameters of the Circumstellar Disk of chi Ophiuchi
• A Pulsational Mechanism for Producing Keplerian Disks around Be Stars
• Stellar Polarimetry: Where Are We and Where Are We Going?

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• A Multi-observing-technique Study of the Dynamical Evolution of the Viscous Disk around the Be Star $\omega$ CMa
• $\nu$ Gem: a hierarchical triple system with an outer Be star
• On the Intrinsic Continuum Linear Polarization of Classical Be Stars: The Effects of Metallicity and One-Armed Density Perturbations
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• Modelling the periodical variations in multiband polarisation and photometry for discs of binary Be stars
• Computing the Photometric and Polarimetric Variability of Be Stars
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• Optical and Near-Infrared Monitoring of Gamma-ray Binaries Hosting Be Stars
• Long-term optical variability of high-mass X-ray binaries. III. Polarimetry
• Polarization of light from fast rotating Wolf-Rayet stars: A Monte Carlo simulations compared to analytical formula