Analysis of the X-ray emission of OB stars II: B stars

Elizaveta Ryspaeva, Alexander Kholtygin

Research output

Abstract

This paper is the second part of an investigation into the mechanism for the origin of X-rays in early-type stars. Archival X-ray observations of 25 B stars, obtained by the XMM-Newton satellite, are analysed. We check two hypotheses on the origin of X-ray emission: the Magnetically Confined Wind Shock Model (MCWS) and Pollock's paradigm. For all studied stars, the mean ratio of the half widths at half maximum to the terminal velocities appears to be $R\approx 0.15-0.20$ in contradiction to Pollock's hypothesis that $R\approx 0.5$. We checked three possible consequences of the MCWS model: correlations between the hardness of the X-ray spectra for B stars and terminal wind velocities, mass loss rates and magnetic fields. It was shown that such correlations are marginal or even absent both for magnetic and non-magnetic B stars.
Original languageEnglish
Article number120
JournalResearch in Astronomy and Astrophysics
Volume19
Issue number8
DOIs
Publication statusPublished - 15 Aug 2019

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B stars
terminal velocity
stars
x rays
shock
wind velocity
XMM-Newton telescope
newton
hardness
magnetic field
analysis
magnetic fields

Cite this

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title = "Analysis of the X-ray emission of OB stars II: B stars",
abstract = "This paper is the second part of an investigation into the mechanism for the origin of X-rays in early-type stars. Archival X-ray observations of 25 B stars, obtained by the XMM-Newton satellite, are analysed. We check two hypotheses on the origin of X-ray emission: the Magnetically Confined Wind Shock Model (MCWS) and Pollock's paradigm. For all studied stars, the mean ratio of the half widths at half maximum to the terminal velocities appears to be $R\approx 0.15-0.20$ in contradiction to Pollock's hypothesis that $R\approx 0.5$. We checked three possible consequences of the MCWS model: correlations between the hardness of the X-ray spectra for B stars and terminal wind velocities, mass loss rates and magnetic fields. It was shown that such correlations are marginal or even absent both for magnetic and non-magnetic B stars.",
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Analysis of the X-ray emission of OB stars II: B stars. / Ryspaeva, Elizaveta ; Kholtygin, Alexander .

In: Research in Astronomy and Astrophysics, Vol. 19, No. 8, 120, 15.08.2019.

Research output

TY - JOUR

T1 - Analysis of the X-ray emission of OB stars II: B stars

AU - Ryspaeva, Elizaveta

AU - Kholtygin, Alexander

PY - 2019/8/15

Y1 - 2019/8/15

N2 - This paper is the second part of an investigation into the mechanism for the origin of X-rays in early-type stars. Archival X-ray observations of 25 B stars, obtained by the XMM-Newton satellite, are analysed. We check two hypotheses on the origin of X-ray emission: the Magnetically Confined Wind Shock Model (MCWS) and Pollock's paradigm. For all studied stars, the mean ratio of the half widths at half maximum to the terminal velocities appears to be $R\approx 0.15-0.20$ in contradiction to Pollock's hypothesis that $R\approx 0.5$. We checked three possible consequences of the MCWS model: correlations between the hardness of the X-ray spectra for B stars and terminal wind velocities, mass loss rates and magnetic fields. It was shown that such correlations are marginal or even absent both for magnetic and non-magnetic B stars.

AB - This paper is the second part of an investigation into the mechanism for the origin of X-rays in early-type stars. Archival X-ray observations of 25 B stars, obtained by the XMM-Newton satellite, are analysed. We check two hypotheses on the origin of X-ray emission: the Magnetically Confined Wind Shock Model (MCWS) and Pollock's paradigm. For all studied stars, the mean ratio of the half widths at half maximum to the terminal velocities appears to be $R\approx 0.15-0.20$ in contradiction to Pollock's hypothesis that $R\approx 0.5$. We checked three possible consequences of the MCWS model: correlations between the hardness of the X-ray spectra for B stars and terminal wind velocities, mass loss rates and magnetic fields. It was shown that such correlations are marginal or even absent both for magnetic and non-magnetic B stars.

KW - stars

KW - early-type — stars

KW - Spectra

KW - X-Ray

UR - http://www.raa-journal.org/docs/papers_accepted/2018-0366.pdf

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DO - 10.1088/1674-4527/19/8/120

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JO - Research in Astronomy and Astrophysics

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SN - 1674-4527

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ER -