Solving the Puzzle of the Massive Star System Theta2 Orionis A
Véronique Petit (West Chester University, USA)
The young, late O star Theta2 OriA has moderately hard X-ray emission and relatively narrow X-ray lines, and has been identified as a Magnetically Channeled Wind Shock (MCWS) source. Hard X-ray flaring, that may have a periodic signal, has also been observed on Theta2 OriA, leading to the suggestion that an exotic new mechanism, of binary-driven magnetic reconnection, could be operating in this spectroscopic binary system. It has also been proposed that the X-ray flaring could be caused by centrifugally-driven magnetic breakout, which is predicted to occur in the MCWS, or X-ray emission from the third visual component of the system. We will present new constraints on the magnetic field properties of the star, and a subpixel spatial analysis of the X-ray emission from the system during both quiescence and flaring. The first of these will be used to place constraints on the degree of magnetic wind confinement and thus on the plausibility of the MCWS mechanism as an explanation for the quiescent X-ray emission. The second of these will be used to assess the contribution to the X-rays – and especially the harder, flaring component of the X-ray emission – from the visual companion of Theta2 OriA.
Back to the seminar webpage.
