NLTE models of line-driven stellar winds I. Method of calculation and first results for O stars

Abstract

New numerical models of line-driven stellar winds of late O stars are presented. Statistical equilibrium (NLTE) equations of the most abundant elements are solved. Properly obtained occupation numbers are used to calculate consistent radiative force and radiative heating terms. Wind density, velocity and temperature are calculated as a solution of model hydrodynamical equations. Contrary to other published models we account for a multicomponent wind nature and do not simplify the calculation of the radiative force (e.g. using force multipliers). We discuss the convergence behaviour of our models. The ability of our models to predict correct values of mass-loss rates and terminal velocities of selected late O stars (mainly giants and supergiants) is demonstrated. The systematic difference between predicted and observed terminal velocities reported in the literature has been removed. Moreover, we found good agreement between the theoretical wind momentum-luminosity relationship and the observed one for Cyg OB2 supergiants.

Accepted for publication in A&A. 17 pages

Cited by in corpus (19)

• Mass loss from late-type WN stars and its Z-dependence: very massive stars approaching the Eddington limit
• Predictions for mass-loss rates and terminal wind velocities of massive O-type stars
• Bright OB stars in the Galaxy IV. Stellar and wind parameters of early to late B supergiants
• Hydrodynamic model atmospheres for WR stars: Self-consistent modeling of a WC star wind
• Towards a unified view of inhomogeneous stellar winds in isolated supergiant stars and supergiant high mass X-ray binaries
• Macroclumping as solution of the discrepancy between Hα and P v mass loss diagnostics for O-type stars
• The Geometry and Dynamical Role of Stellar Wind Bubbles in Photoionised HII Regions
• The winds of the hot massive first stars
• NLTE models of line-driven stellar winds III. Influence of X-ray radiation on wind structure of O stars
• NLTE models of line-driven stellar winds II. O stars in SMC
• X-ray irradiation of the winds in binaries with massive components
• Wind inhibition by X-ray irradiation in HMXBs: the influence of clumping and the final X-ray luminosity
• CNO driven winds of hot first stars
• Multicomponent radiatively driven stellar winds IV. On the helium decoupling in the wind of sigma Ori E
• A hydrodynamic scheme for two-component winds from hot stars
• Hot star wind models with new solar abundances
• NLTE wind models of hot subdwarf stars
• Spherically symmetric NLTE model atmospheres of hot hydrogen-helium first stars
• Current status of NLTE analysis of stellar atmospheres