相关论文: Synthetic photometry for carbon rich giants, I. Hy…

Based on a grid of hydrostatic spherical COMARCS models for cool stars we have calculated observable properties of these objects, which will be mainly used in combination with stellar evolution tracks and population synthesis tools. The…

The evolution and spectral properties of stars on the AGB are significantly affected by mass loss through dusty stellar winds. Dynamic atmosphere and wind models are an essential tool for studying these evolved stars, both individually and…

By using self-consistent dynamic model atmospheres which simulate pulsation-enhanced dust-driven winds of AGB stars we studied in detail the influence of (i) pulsations of the stellar interiors, and (ii) the development of dusty stellar…

We have computed a grid of hydrostatic spherical COMARCS models for C stars covering metallicities from [Z/H]=0 to -2 and values of the carbon excess [C-O] from 6.41 to 9.15, plus some temperature sequences, where the amount of oxygen and…

With the help of model calculations we aim at reproducing the observational photometric findings for a large sample of well-characterised galactic C-type Mira variables losing mass at different rates. We used dynamic model atmospheres,…

In a previous paper, we assembled a collection of medium-resolution spectra of 35 carbon stars, covering optical and near-infrared wavelengths from 400 to 2400 nm. The sample includes stars from the Milky Way and the Magellanic Clouds, with…

We compare high resolution infrared observations of the CO 3-1 bands in the 2.297-2.310 micron region of M dwarfs and one L dwarf with theoretical expectations. We find a good match between the observational and synthetic spectra throughout…

Atmospheres of evolved AGB stars are heavily affected by pulsation, dust formation and mass loss, and they can become very extended. Time series of observed high-resolution spectra proved to be a useful tool to study atmospheric dynamics…

Using a radiative transfer code (DUSTY) parameters of the circumstellar dust shells of 15 hot post-AGB stars have been derived. Combining the optical, near and far-infrared (ISO, IRAS) data of the stars, we have reconstructed their spectral…

We present a database of 45,000 atmospheric models (which will become 80,000 models by the end of the project) with stellar masses between 9 and 120 M$_{\odot}$, covering the region of the OB main sequence and W-R stars in the H-R diagram.…

For amorphous carbon several laboratory extinction data are available, which show quite a wide range of differences due to the structural complexity of this material. We have calculated self-consistent dynamic models of circumstellar…

The properties and the evolution of asymptotic giant branch (AGB) stars are strongly influenced by their mass loss through a stellar wind. This is believed to be caused by radiation pressure due to the absorption and scattering of the…

BA-type supergiants show a high potential as versatile indicators for modern astronomy. The focus here is on the determination of accurate and precise atmospheric parameters for a sample of 35 Galactic BA-type supergiants. Some first…

As part of a reanalysis of galactic Asymptotic Giant Branch (AGB) stars at infrared (IR) wavelengths, we discuss a sample (357) of carbon stars for which mass loss rates, near-IR photometry and distance estimates exist. For 252 sources we…

After a pedagogical introduction to the main concepts of synthetic photometry, colours and bolometric corrections in the Johnson-Cousins, 2MASS, and HST-ACS/WFC3 photometric systems are generated from MARCS synthetic fluxes for various…

(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…

Synthetic photometry is a great tool for studying globular clusters, especially for understanding the nature of their multiple populations. Our goal is to quantify the errors on synthetic photometry that are caused by uncertainties on…

Model carbon star atmospheres and synthetic spectra have been calculated using the recent HCN/HNC vibration rotation linelist of Harris et al. (2002) ApJ, 578, 657. The calculations are repeated using only HCN lines and show that HNC has a…

Ices imprint strong absorption features in the near- and mid-infrared, but until recently they have been studied almost exclusively with spectroscopy toward small samples of bright sources. We show that JWST photometry alone can reveal and…

In this work the optical properties of amorphous carbon (amC) dust condensed around carbon(C)-stars are constrained by comparing the observations for the Large Magellanic Cloud C-stars from the Two Micron All Sky Survey (2MASS) and from the…