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X-Rays from Wolf-Rayet Stars Observed by the Einstein Observatory

Published online by Cambridge University Press:  14 August 2015

W. T. Sanders
Affiliation:
Department of Physics, University of Wisconsin-Madison
J. P. Cassinelli
Affiliation:
Department of Astronomy, University of Wisconsin-Madison
K. A. van der Hucht
Affiliation:
Space Research Lab., The Astronomical Institute at Utrecht

Extract

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Preliminary results of three X-ray surveys are presented. Out of a sample of 20 stars, X-rays were detected from four Wolf-Rayet stars and two 08f+ stars. The detected stars have about the same mean value as 0 stars for the X-ray to total luminosity ratio, LX/L = 10−7, but exhibit a much larger variation about the mean. The spectral energy distributions are also found to be like that of 0 stars in that they do not exhibit large attenuation of X-rays softer than 1 keV. This indicates that for both the 0 stars and WR stars much of the X-ray emission is coming from hot wisps or shocks in the outer regions of the winds and not from a thin source at the base of the wind. The general spectral shape and flux level place severe restrictions on models that attribute the lack of hydrogen emission lines to extremely high temperatures of the gas in the wind.

Type
SESSION 8 — X-RAY DATA — MISCELLANEOUS TOPICS — GENERAL DISCUSSION
Copyright
Copyright © Reidel 1982 

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