X-ray emission from hydrodynamical simulations in non-LTE wind models
Abstract
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 observations. 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.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 2009
- DOI:
- 10.1051/0004-6361/200912642
- arXiv:
- arXiv:0910.3430
- Bibcode:
- 2009A&A...508..841K
- Keywords:
-
- stars: winds;
- outflows;
- stars: mass-loss;
- stars: early-type;
- hydrodynamics;
- X-rays: stars;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 9 pages, accepted for publication in Astronomy and Astrophysics