Related papers: Rusty old stars: a source of the missing interstel…
The giant planet-metallicity correlation revealed that planetary formation depends on the stellar properties. There is growing evidence that it is also valid for smaller hot planets, but it is not clear whether elements other than iron also…
The determination of effective temperatures of very hot central stars (Teff>70000K) by model atmosphere analyses of optical H and He line profiles is afflicted with considerable uncertainty, primarily due to the lack of neutral helium…
Detailed models are presented for the late epoch mid infrared (MIR) emission from collisionally heated grains in the shocked circumstellar gas around SN 1987A. Thermal dust emission from a region of moderate density interior to the thick…
We present mid-infrared Spitzer spectra of eleven planetary nebulae in the Galactic Bulge. We derive argon, neon, sulfur, and oxygen abundances for them using mainly infrared line fluxes combined with some optical line fluxes from the…
Around 2% of all A stars have photospheres depleted in refractory elements. This is hypothesized to arise from a preferential accretion of gas rather than dust, but the specific processes and the origin of the material -- circum- or…
Interstellar dust spans a wide range in size distribution, ranging from ultrasmall grains of a few Angstroms to micrometer-size grains. While the presence of nanometer-size dust grains in the Galactic interstellar medium was speculated six…
The optical/near-IR stellar continuum carries unique information about the stellar population in a galaxy, its mass function and star-formation history. Star-forming regions display rich emission-line spectra from which we can derive the…
For several decades, globular clusters have been considered the best example of simple stellar populations, hosting coeval and chemical homogeneous stars. The last decade of spectroscopic and photometric studies has revealed a more complex…
Although carbon is, together with oxygen and nitrogen, one of the most important elements in the study of galactic chemical evolution its production sites are still poorly known and have been much debated (see e.g. Gustafsson et al. 1999;…
The detection of the 11.3-micron emission feature characteristic of the Si--C stretch in carbon-rich evolved stars reveals that silicon carbide (SiC) dust grains are condensed in the outflows of carbon stars. SiC dust could be a significant…
Among the key parameters defining the ISM of galaxies is the fraction of the metals that are locked up in dust: the metals-to-dust ratio. This ratio bears not only on the ISM and its evolution, but particularly on the origin of cosmic dust.…
The ejecta of the first probably very massive stars polluted the Big Bang primordial element mix with the first heavier elements. The resulting ultra metal-poor abundance distribution provided the initial conditions for the second stars of…
High-resolution X-ray spectroscopy provides a powerful probe of the interstellar medium (ISM), giving direct access to the composition and physical state of dust grains and atomic species in dense environments. We present a study of the gas…
The sizes of interstellar grains are widely distributed, ranging from a few angstroms to a few micrometers. The ultraviolet (UV) and optical extinction constrains the dust in the size range of a couple hundredth micrometers to several…
It is commonly believed that winds of cool giants in their late evolutionary stages are driven by radiative pressure on dust grains, but the actual grain species responsible for driving winds of M-type AGB stars are still a matter of debate…
This paper reviews our current understanding of interstellar dust models, what constitutes a viable dust model, what observational constraints are essential for deriving such model, and the current viable dust models. Interstellar dust…
We present models for the evolution of the elemental abundances in the gas and dust phases of the interstellar medium (ISM) of our Galaxy by generalizing standard models for its dynamical and chemical evolution. In these models, the stellar…
CONTEXT: Manganese is an iron-peak element and although the nucleosynthesis path that leads to its formation is fairly well understood, it remains unclear which objects, SN II and/or SN Ia, that contribute the majority of Mn to the…
Stars with higher aluminum and nitrogen enrichment are often the key pieces for the chemical makeup of multiple populations in almost all globular clusters (GCs). There is also compelling observational evidence that some Galactic components…
Typical galaxies emit about one third of their energy in the infrared. The origin of this emission reprocessed starlight absorbed by interstellar dust grains and reradiated as thermal emission in the infrared. In particularly dusty…