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NLTE models of line-driven stellar winds – III. Influence of X-ray radiation on wind structure of O stars |
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| Authors: | Ji&#;í Krti&#;ka Ji&#;í Kubát |
| Institution: | Ústav teoretickéfyziky a astrofyziky, Masarykova univerzita, CZ-611 37 Brno, Czech Republic;Astronomickýústav AV ?R, Fri?ova 298, CZ-251 65 Ond?ejov, Czech Republic |
| Abstract: | We study the influence of X-rays on the wind structure of selected O stars. For this purpose we use our non-local thermodynamic equilibrium (NLTE) wind code with inclusion of additional artificial source of X-rays, assumed to originate in the wind shocks. We show that the influence of shock X-ray emission on wind mass-loss rate is relatively small. Wind terminal velocity may be slightly influenced by the presence of strong X-ray sources, especially for stars cooler than T We discuss the origin of the L Inclusion of X-rays leads to a better agreement of the model ionization structure with observations. However, we do not find any significant influence of X-rays on P v ionization fraction implying that the presence of X-rays cannot explain the P v problem. We study the implications of modified ionization equilibrium due to shock emission on the line transfer in the X-ray region. We conclude that the X-ray line profiles of helium-like ions may be affected by the line absorption within the cool wind. |
| Keywords: | hydrodynamics stars: early-type stars: mass-loss stars: winds outflows X-rays: stars |