X-ray Emission from Magnetically Torqued Disks of Oe/Be Stars

Abstract

We focus attention on the Oe/Be stars to test the concept that the disks of these stars form by magnetic channeling of wind material toward the equator. Calculations are made of the X-rays expected from the Magnetically Torqued Disk (MTD) model for Be stars discussed by Cassinelli et al. (2002), by Maheswaran (2003), and by Brown et al. (2004). The dominant parameters in the model are the $\beta$ value of the velocity law, the rotation rate of the star, $S_o$, and the ratio of the magnetic field energy density to the disk gravitational energy density, $\gamma$. The model predictions are compared with the $ROSAT$ observations obtained for an O9.5 star $\zeta$ Oph from \Berghofer et al. (1996) and for 7 Be stars from Cohen et al. (1997). Extra considerations are also given here to the well studied Oe star $\zeta$ Oph for which we have $Chandra$ observations of the X-ray line profiles of the triad of He-like lines from the ion Mg XI.

arXiv comment28 pages with 6 figures. Accepted for publication in ApJ

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Cited by in corpus (9)

• X-Ray Spectroscopy of Stars
• Early magnetic B-type stars: X-ray emission and wind properties
• The Effects of Clumps in Explaining X-ray Emission Lines from Hot Stars
• The XMM-Newton EPIC X-ray Light Curve Analysis of WR 6
• The Correlation between X-Ray Line Ionization and Optical Spectral Types of the OB Stars
• Intriguing X-ray and optical variations of the gamma Cas analog HD45314
• X-ray emission from massive stars with magnetic fields
• Faraday Rotation Distributions from Stellar Magnetism in Wind-Blown Bubbles
• Interactions in massive binary stars as seen by interferometry