A possible nonthermal X-ray emission from γ Cas analogues stars

Abstract: We analyze the archival XMM-Newton X-ray observations of 15 γ Cas analogue stars and two candidates for such objects. The EPIC spectra of the considered stars in the range of 0.2-8 keV were extracted and fitted by different models. Our estimates show that assuming the X-ray emission from γ Cas analogues to be totally thermal, their model plasma temperatures can reach anomalously high values. However including an additional power components to the model spectra leads to significant decreasing of the plasma temperatures. The spectral index of the power component is about 1.5, and the fraction of this in the total model flux is rather large (50-90%). Moreover, it decreases with expanding temperature of the X-ray emitting plasma as compared to typical OB stars. We conclude that γ Cas analogues can produce nonthermal X-ray emission within the framework of the Chen & White (1991) model, while if the nonthermal X-rays from typical OB stars exists, they should be generated by different processes.

Location
Deutsche Nationalbibliothek Frankfurt am Main
Extent
Online-Ressource
Language
Englisch

Bibliographic citation
A possible nonthermal X-ray emission from γ Cas analogues stars ; volume:30 ; number:1 ; year:2021 ; pages:132-143 ; extent:12
Open astronomy ; 30, Heft 1 (2021), 132-143 (gesamt 12)

Creator
Ryspaeva, Elizaveta B.
Kholtygin, Alexander F.

DOI
10.1515/astro-2021-0018
URN
urn:nbn:de:101:1-2405281621331.813017590522
Rights
Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
Last update
14.08.2025, 10:57 AM CEST

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Associated

  • Ryspaeva, Elizaveta B.
  • Kholtygin, Alexander F.

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