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Related papers: Developing a self-consistent AGB wind model: I. Ch…

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High spatial resolution techniques have given valuable insights into the mass loss mechanism of AGB stars, which presumably involves a combination of atmospheric levitation by pulsation-induced shock waves and radiation pressure on dust.…

Solar and Stellar Astrophysics · Physics 2016-10-19 Susanne Höfner , Sara Bladh , Bernhard Aringer , Rajeev Ahuja

We present calculations for a magnetised hybrid wind model for Asymptotic Giant Branch (AGB) stars. The model incorporates a canonical Weber-Davis (WD) stellar wind with dust grains in the envelope of an AGB star. The resulting hybrid…

Solar and Stellar Astrophysics · Physics 2014-09-15 Anand Thirumalai , Jeremy S. Heyl

We aim to constrain the dust mass and grain sizes in the interaction regions between the stellar winds and the ISM around asymptotic giant branch stars. By describing the dust in these regions, we aim to shed light on the role of low mass…

Astrophysics of Galaxies · Physics 2022-09-21 M. Maercker , T. Khouri , M. Mecina , E. De Beck

Models describing dust-driven winds are important for understanding the physical mechanism and properties of mass loss on the asymptotic giant branch. These models are becoming increasingly realistic with more detailed physics included, but…

Astrophysics · Physics 2008-03-18 Christer Sandin

We present three-component wind models for carbon rich pulsating AGB stars. In particular we study the effects of drift in models of long-period variables, meaning that the dust is allowed to move relative to the gas (drift models). In…

Astrophysics · Physics 2009-11-07 C. Sandin , S. Hoefner

Stellar winds observed in asymptotic giant branch (AGB) stars are usually attributed to a combination of stellar pulsations and radiation pressure on dust. Shock waves triggered by pulsations propagate through the atmosphere, compressing…

Solar and Stellar Astrophysics · Physics 2015-06-23 S. Bladh , S. Höfner , B. Aringer , K. Eriksson

We have combined time dependent hydrodynamics with a two-fluid model for dust driven AGB winds. Our calculations include self-consistent gas chemistry, grain formation and growth, and a new implementation of the viscous momentum transfer…

Astrophysics · Physics 2009-11-06 Yvonne Simis , Vincent Icke , Carsten Dominik

A proper treatment of the non-equilibrium dust formation process is crucial in models of AGB star winds. In this paper the micro-physics of this process is treated in detail, with an emphasis on the effects of drift (drift models). We…

Astrophysics · Physics 2007-05-23 C. Sandin , S. Hoefner

There are strong observational indications that the dense slow winds of cool luminous AGB stars are driven by radiative pressure on dust grains which form in the extended atmospheres resulting from pulsation-induced shocks. For carbon…

Solar and Stellar Astrophysics · Physics 2011-02-28 Susanne Höfner

Low- and intermediate-mass stars go through a period of intense mass-loss at the end of their lives in a phase known as the asymptotic giant branch (AGB). During the AGB a significant fraction of their initial mass is expelled in a stellar…

Solar and Stellar Astrophysics · Physics 2015-05-13 T. Khouri , L. B. F. M. Waters , A. de Koter , L. Decin , M. Min , B. L. de Vries , R. Lombaert , N. L. J. Cox

The purpose of this work is to present an extensive grid of dynamical atmosphere and wind models for M-type AGB stars, covering a wide range of relevant stellar parameters. We used the DARWIN code, which includes frequency-dependent…

Solar and Stellar Astrophysics · Physics 2019-07-10 S. Bladh , S. Liljegren , S. Höfner , B. Aringer , P. Marigo

We compare observations of AGB stars and predictions of the Elitzur & Ivezic (2001) steady-state radiatively driven dusty wind model. The model results are described by a set of similarity functions of a single independent variable, and…

Solar and Stellar Astrophysics · Physics 2015-05-18 Zeljko Ivezic , Moshe Elitzur

Dust grains forming in the extended atmospheres of AGB stars are critical for the heavy mass loss of these cool luminous giants, as they provide radiative acceleration for the stellar winds. Characteristic mid-IR spectral features indicate…

Solar and Stellar Astrophysics · Physics 2019-03-27 Susanne Höfner , Bernd Freytag

The heavy mass loss observed in evolved asymptotic giant branch stars is usually attributed to a two-step process: atmospheric levitation by pulsation-induced shock waves, followed by radiative acceleration of newly formed dust grains.…

Solar and Stellar Astrophysics · Physics 2017-11-08 S. Bladh , C. Paladini , S. Höfner , B. Aringer

Late asymptotic giant branch (AGB) and early post-AGB stars which are progenitors of planetary nebulae lose mass at extremely high rate, in what is termed a superwind. We show that the existence of this superwind during the post-AGB phase…

Astrophysics · Physics 2007-05-23 Noam Soker , Amos Harpaz

The atmospheres and winds of C-type AGB stars are modeled with the 1D spherically symmetric radiation-hydrodynamical code DARWIN. To explore the metallicity-dependence of mass loss we calculate model grids at three different chemical…

Solar and Stellar Astrophysics · Physics 2019-03-20 S. Bladh , K. Eriksson , P. Marigo , S. Liljegren , B. Aringer

The slow, dense winds observed in evolved asymptotic giant branch (AGB) stars are usually attributed to a combination of dust formation in the dynamical inner atmosphere and momentum transfer from stellar photons interacting with the newly…

Solar and Stellar Astrophysics · Physics 2019-06-26 Sara Bladh

I discuss the relationship between mass loss and nucleosynthesis on the Asymptotic Giant Branch (AGB). Because of thermal pulses and possibly other mixing processes, products of nucleosynthesis can be brought to the surface of AGB stars,…

Astrophysics · Physics 2015-05-13 Jacco Th. van Loon

We argue that the energy injection of pulsations may be of greater importance to the mass-loss rate of AGB stars than metallicity, and that the mass-loss trend with metallicity is not as simple as sometimes assumed. Using our detailed…

Astrophysics · Physics 2011-07-21 L. Mattsson , R. Wahlin , S. Höfner , K. Eriksson

It is important to properly describe the mass-loss rate of AGB stars, in order to understand their evolution from the AGB to PN phase. The primary goal of this study is to investigate the influence of metallicity on the mass-loss rate,…

Solar and Stellar Astrophysics · Physics 2015-05-30 Mikako Matsuura