The wind geometry of the Wolf-Rayet star HD 191765

Autor:	Antonio Mário Magalhães, M. J. Taylor, M. J. Wolff, Karen S. Bjorkman, Kenneth H. Nordsieck, R. F. Schulte-Ladbeck
Rok vydání:	1992
Předmět:	Physics Opacity Stellar atmosphere Astronomy and Astrophysics Geometry Astrophysics Polarization (waves) Spectral line Wolf–Rayet star Space and Planetary Science Ionization Astrophysics::Solar and Stellar Astrophysics Emission spectrum Circular symmetry
Zdroj:	The Astrophysical Journal. 387:347
ISSN:	1538-4357 0004-637X
DOI:	10.1086/171087
Popis:	A time-dependent spectropolarimetric data set of HD 191765 in the wavelength range 3159-7593 A is presented. At all epochs the present observations display a large and strongly wavelength-dependent continuum polarization and reduced levels of polarization across the emission lines. The data imply a significant intrinsic continuum polarization which requires a general deviation of the electron distribution from spherical symmetry. The global shape is quite stable as a function of time; small fluctuations may arise from localized density/temperature changes. The line polarizations are consistent with an axisymmetric wind geometry and ionization stratification. A qualitative model for polarization in a Wolf-Rayet atmosphere is developed. It is argued that the blueward rise of the continuum polarization in HD 191765 can be explained if the density in the wind is high, resulting in a competition of thermal and electron-scattering continuum opacity in the vertical.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::6d5090e9f5fc85771b5f10baa255094b https://doi.org/10.1086/171087 Zobrazit plný text záznamu