X-ray emission from hydrodynamical simulations in non-LTE wind models

J. Krticka, A. Feldmeier, L. M. Oskinova, J. Kubat, W.-R. Hamann

Ustav teoreticke fyziky a astrofyziky, Masarykova univerzita, Kotlarska 2, CZ-611 37 Brno, Czech Republic
Institut fur Physik und Astronomie, Universitat Potsdam, Karl-Liebknecht-Strasse 24/25, 14476 Potsdam-Golm, Germany
Astronomicky ustav, Akademie ved Ceske republiky, CZ-251 65 Ondrejov, Czech Republic

Hot stars are sources of X-ray emission originating in their winds. Although hydrodynamical simulations that are able to predict this X-ray emission are available, the inclusion of X-rays in stationary wind models is usually based on simplifying approximations. To improve this, we use results from time-dependent hydrodynamical simulations of the line-driven wind instability (seeded by the base perturbation) to derive the analytical approximation of X-ray emission in the stellar wind. We use this approximation in our non-LTE wind models and find that an improved inclusion of X-rays leads to a better agreement between model ionization fractions and those derived from servations. Furthermore, the slope of the L_x-L relation is in better agreement with observations, however the X-ray luminosity is underestimated by a factor of three. We propose a possible solution for this discrepancy.

Reference: A&A, in press
Status: Manuscript has been accepted

Weblink: http://xxx.lanl.gov/abs/0910.3430


Email: krticka@physics.muni.cz