Mass fluxes for O stars

Astrophysics Group, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, UK e-mail: l.lucy@imperial.ac.uk

Received: 14 February 2007
Accepted: 26 March 2007

Abstract

The theory of moving reversing layers for hot stars is updated to include an extensive line list, a radiative boundary condition from static model atmospheres, line transfer by scattering, and continuation to supersonic velocities. A Monte Carlo technique determines the theory's eigenvalue J, the mass flux, and the derived J's are in good agreement with the wind models of Pauldrach et al. (2001, A&A, 375, 161). The solutions' sensitivity to the photospheric microturbulent velocity v_t reveals that this parameter has a throttling effect on J: turbulent line-broadening in the quasi-static layers reduces the radiation force available to accelerate matter through the sonic point. If photospheric turbulence approaches sonic velocities, this mechanism reduces mass loss rates by factors 3, which would partly account for the reduced rates found observationally for clumpy winds.