Origin of the broad H-alpha wings in symbiotic binaries.
Authors:
A. Skopal
Image & caption:
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Image caption::
Left panel shows a scheme of the structure of the hot stellar object during active phase of a symbiotic binary. The accretor is encompassed by an optically thick flared disk at its equator, while from a certain latitude to the accretor poles, we observe a fast ionized wind. A direct indication of such the bipolar wind is represented by the broad wings of H-alpha profiles. Right panel compares the observed extended wing during active phase of Z And, fitted with a model of the bipolar wind.
Description:
The extreme broad emission wings of the hydrogen H-alpha line in the spectra of interacting binaries represents a pivotal problem of their astrophysics. To date models considering rotating discs, scattering on free electrons and/or radiative damping in lines were elaborated. Recently a theory of the Raman scattering Ly-beta photons on neutral atoms of hydrogen was developed. The aim of the current study was to suggest a rivaling alternative to explain the significant broadening of the H-alpha line during outbursts that is consistent with the structure of the active object. In the model I assumed that the broad H-alpha wings are produced by ionized hydrogen. I found that the broad wings can be formed in the high-velocity stellar wind from the hot star. By this way the active star loses a fraction of its mass at rates of approximately 1x10E-6 solar masses per year. The radiation produced by the H-alpha line is consistent with the radio observations. The suggested model has implications for investigation of the mass-loss from other astrophysical objects, as AGB stars, planetary nebulae or the active galactic nuclei. In the symbiotic star research this study represents an important ingredient of the structure of active objects
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SAS
