Related papers: Rusty old stars: a source of the missing interstel…
The past century of interstellar dust has brought us from first ignoring it to finding that it is an important component of the interstellar medium and plays an important role in the evolution of galaxies, the formation of stars and…
It is well-established that the vast majority of metal-poor Galactic halo stars shows evidence for enrichment by solely massive stars. Recent observations have identified more varied behavior in the pattern of elemental abundances measured…
We present a study on the prospects of observing carbon, sulfur, and other lower abundance elements (namely Al, Ca, Ti and Ni) present in the interstellar medium using future X-ray instruments. We focus in particular on the detection and…
This work is part of an ongoing effort aiming at identifying the actual wind-drivers among the dust species observed in circumstellar envelopes. In particular, we focus on the interplay between a strong stellar radiation field and the dust…
We study the dust present in 56 Galactic planetary nebulae (PNe) through their iron depletion factors, their C/O abundance ratios (in 51 objects), and the dust features that appear in their infrared spectra (for 33 objects). Our sample…
This paper assesses the implications of a recent discovery (Jenkins 2009) that atomic oxygen is being depleted from diffuse interstellar gas at a rate that cannot be accounted for by its presence in silicate and metallic oxide particles. To…
Around 16% of the solar-like stars in our neighbourhood show IR-excesses due to debris discs and a fraction of them are known to host planets. We aim to determine in a homogeneous way the metallicity of a sample of stars with known debris…
The iron depletion factors found in Galactic planetary nebulae (PNe) span over two orders of magnitude, suggesting that there are differences in the grain formation and destruction processes from object to object. We explore here the…
Atomic diffusion may lead to heavy element accumulation inside stars in certain specific layers. Iron accumulation in the Z-bump opacity region has been invoked by several authors to quantitatively account for abundance anomalies observed…
A study of gas-phase element abundances reported in the literature for 17 different elements sampled over 243 sight lines in the local part of our Galaxy reveals that the depletions into solid form (dust grains) are extremely well…
Dust is formed in the expanding atmosphere during late stages of stellar evolution. Dust influences the dynamics and thermodynamics of the stellar atmosphere by its opacity. The dust opacity depends both on the optical properties of the…
We aim at assessing what are the most dominant dust species or types, including silicate and iron oxide grains present in the ISM, by using recent observations of dust depletion of galaxies at various evolutionary stages. We use the…
We present preliminary results of a detailed chemical abundance analysis for a sample of solar-type stars known to exhibit excess infrared emission associated with dusty debris disks. Our sample of 28 stars was selected based on results…
Outflows of pre-main-sequence stars drive shocks into molecular material within 0.01 - 1 pc of the young stars. The shock-heated gas emits infrared, millimeter and submillimeter lines of many species including. Dust grains are important…
We consider the depletion of elements from the interstellar gas onto a population of very small dust grains. Adopting a grain model in which of order 4% of the cosmic C abundance is in grains with radii <= 10 Angstroms, we find that the…
Accurate chemical compositions of star-forming regions are a critical diagnostic tool to characterize the star formation history and gas flows which regulate galaxy formation. However, the abundance discrepancy factor (ADF) between…
Heavy chemical elements such as iron in the intra-cluster medium (ICM) of galaxy clusters are a signpost of the interaction between the gas and stellar components. Observations of the ICM metallicity in present-day massive systems, however,…
We present high-resolution Magellan/MIKE spectroscopy of the brightest star in the ultra-faint dwarf galaxy Leo IV. We measure an iron abundance of [Fe/H] = -3.2, adding to the rapidly growing sample of extremely metal-poor stars being…
Ultraviolet spectra of stars recorded by orbiting observatories since the 1970's have revealed absorption features produced by atoms in their favored ionization stages in the neutral ISM of our Galaxy. Most elements show abundances relative…
We analyse observational correlations for three elements entering into the composition of interstellar silicate and oxide grains. Using current solar abundances (Asplund et al. 2009), we convert the gas-phase abundances into dust-phase…