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

• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2019,（8）
• 页码范围: 141-148
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-4527/19/8/120

摘要

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 ≈ 0.15-0.20 in contradiction to Pollock's hypothesis that R ≈ 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.