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arXiv · astro-ph/0212313

X ray emission line profile modeling of hot stars

Roban H. Kramer·Stephanie K. Tonnesen·David H. Cohen·Stanley P. Owocki·Asif ud-Doula·Joseph J. MacFarlane
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Abstract

The launch of high-spectral-resolution x-ray telescopes (Chandra, XMM) has provided a host of new spectral line diagnostics for the astrophysics community. In this paper we discuss Doppler-broadened emission line profiles from highly supersonic outflows of massive stars. These outflows, or winds, are driven by radiation pressure and carry a tremendous amount of kinetic energy, which can be converted to x rays by shock-heating even a small fraction of the wind plasma. The unshocked, cold wind is a source of continuum opacity to the x rays generated in the shock-heated portion of the wind. Thus the emergent line profiles are affected by transport through a two-component, moving, optically thick medium. While complicated, the interactions among these physical effects can provide quantitative information about the spatial distribution and velocity of the x-ray-emitting and absorbing plasma in stellar winds. We present quantitative models of both a spherically-symmetric wind and a wind with hot plasma confined in an equatorial disk by a dipole magnetic field.

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Roban H. Kramer, Stephanie K. Tonnesen, David H. Cohen, Stanley P. Owocki, Asif ud-Doula, Joseph J. MacFarlane. 2002-12-13. X ray emission line profile modeling of hot stars. https://doi.org/10.1063/1.1535240

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