Dust formation in winds of long-period variables IV. Atmospheric dynamics and mass loss

Autor(en)

Susanne Höfner, Ernst Dorfi

Abstrakt

We have calculated radiation-hydrodynamical models of the atmosphere and circumstellar dust shell of C-rich long-period variables which include a detailed description of the dust formation process. We discuss the time-dependent behaviour of the circumstellar envelope (e.g. multiperiodicity) and its relevance for observational properties like near-IR light curves and investigate the time-averaged mass loss characteristics of a sample of models satisfying radius-luminosity-mass and period-luminosity relations. The results can be summarized as follows: The dependence of the mass loss rate on stellar parameters predicts a strong increase of mass loss as stars evolve along the AGB. The models presented agree reasonably well with mean mass loss-period relations deduced from observations of Mira stars and the observed scatter of mass loss rates for a given period can be understood in terms of pulsation amplitude or non-linearities of the wind mechanism. The wind velocities show a good correlation with the quantity (?d/?g) L*/M* which characterizes the strength of radiation pressure on dust relative to gravitation.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Uppsala University

Journal

Astronomy & Astrophysics

Band

319

Seiten

648-654

Anzahl der Seiten

7

ISSN

0004-6361

Publikationsdatum

1997

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/08a0cb6f-eada-4bc0-bc54-a0ca70a618d3