Letter to the Editor

Hot star wind models with new solar abundances

¹ Ústav Teoretické Fyziky a Astrofyziky PřF MU, 611 37 Brno, Czech Republic e-mail: krticka@physics.muni.cz
² Astronomický Ústav, Akademie Věd České Republiky, 251 65 Ondřejov, Czech Republic

Received: 20 November 2006
Accepted: 11 January 2007

Abstract

We compare the hot-star wind models calculated by assuming older solar-abundance determination with models calculated using the recently published values derived from 3D hydrodynamical model atmospheres. We show that the use of new abundances with lower metallicity improves the agreement between wind observation and theory in several aspects. (1) The predicted wind mass-loss rates are lower by a factor of 0.76. This leads to better agreement with mass-loss rates derived from observational analysis that takes the clumping into account. (2) As a result of the lowering of mass-loss rates, there is better agreement between the predicted modified wind momentum-luminosity relationship and that derived from observational analysis that takes the clumping into account. (3) Both the lower mass fraction of heavier elements and lower mass-loss rates lead to a decrease in opacity in the X-ray region. This influences the prediction of the X-ray line profile shapes. (4) There is better agreement between predicted ionization fractions and those derived from observations.