Dust formation in stellar winds. III - Self-consistent models for dust-driven winds around C-stars

Self-consistent models for spherically symmetric stationary dust-driven winds around late type carbon stars are constructed by solving numerically the coupled system of equations for the hydrodynamics, radiative transfer (in analytical approximation) and dust formation and growth. The calculated model characteristics with respect to mass-loss rates, terminal velocities of the wind, optical depths of the dust shell, injection rate of grains into the interstellar medium and degree of condensation of carbon into grains agree well with observed properties of circumstellar shells. This strongly suggests that dust condensation is the driving mechanism for the wind for this class of objects.