Chemical models of AGB winds

2D Models for Dust-driven AGB Star Winds

New axisymmetric (2D) models for dust-driven winds of C-stars are presented which include hydrodynamics with radiation pressure on dust, equilibrium chemistry and time-dependent dust formation with coupled grey Monte Carlo radiative transfer. Considering the most simple case without stellar pulsation (hydrostatic inner boundary condition) these models reveal a more complex picture of the dust f...

The Structure of Winds in Agb Stars

Most dusty winds are described by a set of similarity functions of a single independent variable that can be chosen as τV, the overall optical depth at visual. The self-similarity implies general scaling relations among the system parameters, in agreement with observations. Dust drift through the gas has a major impact on the structure of most winds.

Non-spherical dust driven winds of slowly rotating AGB stars

We propose a new mechanism to explain an asymmetric mass loss for C-rich asymptotic giant branch (AGB)stars based on the effect how rotation modifies dust driven winds. Even small deviations from spherical symmetry introduced by slow rotations are amplified in the zone of dust condensation due to the non-linear behaviour and the strong temperature and density dependence of the dust formation pr...

Evidence for bipolar jets in late stages of AGB winds

Bipolar expansion at various stages of evolution has been recently observed in a number of AGB stars. The expansion is driven by bipolar jets that emerge late in the evolution of AGB winds. The wind traps the jets, resulting in an expanding, elongated cocoon. Eventually the jets break-out from the confining spherical wind, as recently observed in W43A. This source displays the most advanced evo...

Winds, Bubbles, . . . But Magnetized: Solutions For High Speed Post-Agb Winds And Their Extreme Collimation