Dust formation in winds of long-period variables. V. The influence of micro-physical dust properties in carbon stars

TL;DR

This study uses self-consistent models to explore how micro-physical dust properties affect wind dynamics and observable features in carbon-rich AGB stars, highlighting the importance of dust parameters in mass loss processes.

Contribution

It introduces detailed dynamical models that incorporate frequency-dependent radiation hydrodynamics and dust formation to assess the impact of dust micro-physics on stellar winds.

Findings

Dust parameters significantly influence wind velocity and mass loss rates.

Micro-physical dust properties determine whether dust-driven winds occur.

Observable near-infrared colors are affected by dust properties.

Abstract

We present self-consistent dynamical models for dust-driven winds of carbon-rich AGB stars. The models are based on the coupled system of frequency-dependent radiation hydrodynamics and time-dependent dust formation. We investigate in detail how the wind properties of the models are influenced by the micro-physical properties of the dust grains that are required by the description of grain formation. The choice of dust parameters is significant for the derived outflow velocity, the degree of condensation and the resulting mass loss rates of the models. In the transition region between models with and without mass loss the choice ofmicro-physical parameters turns out to be very significant for whether a particular set of stellar parameters will give rise to a dust-driven mass loss or not. We also calculate near-infrared colors to test how the dust parameters influence the observable properties of the models, however, at this point we do not attempt to fit particular stars.