The Be Star Newsletter, Volume 40 - November 2009

[Previous Abstract] [Table of Abstracts] [Next Abstract]

[Table of Contents] [Be Star Newsletter Home]


Using Optical/Near-Infrared Interferometric Polarimetry to Place Constraints on the Disks Surrounding Be Stars

F. E. Mackay1, N. M. Elias II2,3,4, C. E. Jones1, and T. A. A. Sigut1

1 Department of Physics and Astronomy, The University of Western Ontario, London, Ontario N6A 3K7, Canada
2 Zentrum für Astronomie der Universität Heidelberg Landessternwarte, Königstuhl 12, 69117 Heidelberg, Germany
3 Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
4 National Radio Astronomy Observatory, Array Operations Center, P.O. Box O, 1003 Lopezville Road, Socorro NM 87801-0387, USA

We present predictions for the normalized Stokes visibilities of a Be star disk, as would be measured by an interferometric polarimeter. Using both a simple geometric model for the disk as well as a more complex radiative transfer model, we investigate, in detail, the effect of each of the model parameters on the resultant normalized Stokes visibilities. We find normalized visibility amplitudes for the total star and disk system of ∼ 10-2–10-3 at shorter baselines, and ∼ 10-3–10-4 at longer baselines, requiring, at small and moderate baselines, an accuracy for interferometric polarization observations better than ∼ 10-3–10-4, including all random and systematic errors. Provided this level of accuracy is attainable, we find that the Stokes Q visibility may be important both for the removal of model degeneracies present when considering the intensity alone, as well as for providing an estimate of the inclination angle of the disk.

ApJ, 2009, 704, 591


Last modified: November 5, 2009

David McDavid
dam3ma@virginia.edu