Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-30T07:48:18.703Z Has data issue: false hasContentIssue false

Intrinsic Linear Polarization of Be Stars as a Function of v sin i

Published online by Cambridge University Press:  14 August 2015

R. Poeckert
Affiliation:
University of Western Ontario, London, Ontario, Canada
J. M. Marlborough
Affiliation:
University of Western Ontario, London, Ontario, Canada

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The polarization of 48 Be stars has been measured in two bands near Hα with the aim of determining the relation between intrinsic polarization and v sin i. A technique developed by Poeckert (1975) is used to remove the effect of interstellar polarization. It is found that intrinsic polarization depends strongly on v sin i; stars with low v sin i having little or no polarization. We have calculated the i dependence of linear polarization for a disk model envelope and find that the polarization is proportional to τe sin2i when the disk is optically thin (τe is a characteristic electron scattering optical depth). A comparison of the observed relation between intrinsic polarization and v sin i, and that predicted for the disk model is illustrated. We find that an envelope with an electron density of ≤5 × 1011 cm−3 can account for the degree of intrinsic polarization observed in all the program stars. The fact that stars of low v sin i have little intrinsic polarization is evidence for the assumption that these stars are seen pole-on and that the envelopes around these stars are axi-symmetric. No apparent difference between pole-on stars and extreme Be stars was obtained.

Type
Part III: New Observational Techniques
Copyright
Copyright © Reidel 1976 

References

Poeckert, R.: 1975, Astrophys. J. 196, 777.CrossRefGoogle Scholar