Abstract—In the paper the possibility of the presence of a non-thermal component described by a power law spectrum in the X-ray spectra of OB stars is investigated. The low-resolution spectra of 101 OB stars obtained using the EPIC camera on the XMM satellite are analyzed. It is concluded that the contribution of the non-thermal component of X-ray emission can be significant and even determining for the stars similar to γ Cas. The inclusion of the non-thermal component in the model X-ray spectra reduces the temperature of the thermal components of the X-ray plasma of such stars down to typical for OB stars values. The contribution of the non-thermal component can also be significant for binary stars with colliding stellar winds and for Of?p stars.
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www.cosmos.esa.int/web/xmm-newton.
Usually (see, for example, Naze et al. (2014)) when modeling the spectra of OB stars, this parameter is fixed and assumed to be equal to 1 (solar abundance). We did not fix this parameter, since the element abundances in the X-ray-emitting plasma may differ from the solar.
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The authors express their gratitude to the reviewer for comments that improves the text of the article.
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This research was supported by the Russian Foundation for Basic Research, grant no. 19-02-00311 А.
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Ryspaeva, E.B., Kholtygin, A.F. Contribution of a Non-Thermal Component to the X-Ray Emission of OB Stars. Astrophys. Bull. 75, 127–138 (2020). https://doi.org/10.1134/S199034132002011X
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DOI: https://doi.org/10.1134/S199034132002011X