Related papers: Dust in AGB stars: transparent or opaque?
We calculated theoretical evolutionary sequences of asymptotic giant branch (AGB) stars, including formation and evolution of dust grains in their circumstellar envelope. By considering stellar populations of the Large Magellanic Cloud…
This paper reports on computational evidence for the formation of cloud-like dust structures around C-rich AGB stars. This spatio-temporal structure formation process is caused by a radiative/thermal instability of dust forming gases as…
Most dusty winds are described by a set of similarity functions of a single independent variable that can be chosen as the overall optical depth at visual. The self-similarity implies general scaling relations among the system parameters,…
(abbreviated) Measuring the surface abundances of AGB stars is an important tool for studying the effects of nucleosynthesis and mixing in the interior of low- to intermediate mass stars during their final evolutionary phases. The…
We present a novel approach to address dust production by low- and intermediate-mass stars. We study the asymptotic giant branch (AGB) phase, during which the formation of dust takes place, from the perspective of post-AGB and planetary…
S-type AGB stars are thought to be in the transitional phase between M-type and C-type AGB stars. Because of their peculiar chemical composition, one may expect a strong influence of the stellar C/O ratio on the molecular chemistry and the…
The driving mechanism of the AGB superwind has become controversial in recent years. The efficacy of dust-driven mass loss has been queried. Spitzer observation of AGB stars in Local Group Galaxies show the surprising result that at low…
We observed mid-infrared (7.5-22 mum) spectra of AGB stars in the globular cluster 47 Tuc with the Spitzer telescope and find significant dust features of various types. Comparison of the characteristics of the dust spectra with the…
We measure the integrated contributions of dusty AGB stars and other luminous red mid-IR sources to the mid-IR luminosities of 6 galaxies (M81, NGC 2403, NGC 300, M33 and the Magellanic Clouds). We find the dusty AGB stars whose mid-IR…
A parameter study of the spectral evolution of a typical post-AGB star, with particular emphasis on the evolution of the infrared colours, is presented. The models are based on the latest evolutionary tracks for hydrogen burning post-AGB…
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…
Encoded in the time- and wavelength dependent properties of pulsating AGB stars are the underlying fundamental parameters of mass, composition and evolutionary state. However, the standard technique of placing stars on a HR diagram, even…
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…
Interstellar dust forms during stellar mass-loss events, occurring either during a star's giant phase or during supernova explosions. This PhD thesis provides an in-depth investigation into the theory of dust condensation and growth,…
The goal of this study is to reconstruct the evolution and the dust formation processes during the final AGB phases of a sample of carbon-rich, post-AGB Galactic stars, with particular attention to the determination of the past mass-loss…
Recent advances in the modelling of stellar winds driven by radiation pressure make it possible to fit many wind-sensitive features in the UV spectra of hot stars, opening the way for a hydrodynamically consistent determination of stellar…
Emission and absorption line observations of molecules in late-type stars are a vital component in our understanding of stellar evolution, dust formation and mass loss in these objects. The molecular composition of the gas in the…
The basic mechanism responsible for the widespread condensation of MgS in the outflows from carbon rich stars on the tip of the AGB is discussed with the aim of developing a condensation model that can be applied in model calculations of…
Low- and intermediate-mass stars on the asymptotic giant branch (AGB) account for a significant portion of the dust and chemical enrichment in their host galaxy. Here we present ALMA observations of the continuum emission at 1.24 mm around…
[Abridged] AGB stars are significant contributors to the metal enrichment of the interstellar medium. In this paper, we adapted models from advanced RHD simulations as input for radiative transfer software to create synthetic observables. A…