ChandraHETGS Multiphase Spectroscopy of the Young Magnetic O Starθ1Orionis C

Abstract
We report on four Chandra grating observations of the oblique magnetic rotator θ1 Ori C (O5.5 V), covering a wide range of viewing angles with respect to the star's 1060 G dipole magnetic field. We employ line-width and centroid analyses to study the dynamics of the X-ray-emitting plasma in the circumstellar environment, as well as line-ratio diagnostics to constrain the spatial location, and global spectral modeling to constrain the temperature distribution and abundances of the very hot plasma. We investigate these diagnostics as a function of viewing angle and analyze them in conjunction with new MHD simulations of the magnetically channeled wind shock mechanism on θ1 Ori C. This model fits all the data surprisingly well, predicting the temperature, luminosity, and occultation of the X-ray-emitting plasma with rotation phase.