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We investigate X-ray emission properties of the peculiar X-ray source Theta2Ori A in the Orion trapezium region using more than 500 ksec of HETGS spectraldata in the quiescent state. The amount of exposure provides tight constraintson several important diagnostics involving O, Ne, Mg, and Si line flux ratiosfrom He-like ion triplets, resonance line ratios of the H- and He-like linesand line widths. Accounting for the influence of the strong UV radiation fieldof the O9.7V star we can now place the He-like line origin well within twostellar radii of the O-star's surface. The lines are resolved with average linewidths of 341+-38 km/s confirming a line origin relatively close to the stellarsurface. In the framework of standard wind models this implies a rather weak,low opacity wind restricting wind shocks to temperatures not much larger than2x10^6 K. The emission measure distribution of the X-ray spectrum, as reportedpreviously, includes very high temperature components which are not easilyexplained in this framework. The X-ray properties are also not consistent withcoronal emissions from an unseen low-mass companion nor with typical signaturesfrom colliding wind interactions. The properties are more consistent with X-raysignatures observed in the massive Trapezium star Theta1 Ori C which hasrecently been successfully modeled with a magnetically confined wind model.

Detailed X-Ray Line Properties of Theta2 Ori A in Quiescence