Related papers: The essential elements of dust evolution: A viable…
The presence of dust in the intracluster medium (ICM) has been a long-standing problem that is still awaiting elucidation. Direct observational diagnostics are rather challenging (though not impossible) either because of a sparse…
The origin of bistable solutions in the kinetic equations describing the chemistry of dense interstellar clouds is explained as being due to the autocatalysis and feedback of oxygen nuclei from the oxygen dimer (O2). We identify four…
We have studied the O and Ne absorption features in the X-ray spectrum of Cyg X-2 observed with the Chandra LETG. The O absorption edge is represented by the sum of three absorption-edge components within the limit of the energy resolution…
We study metal depletion due to dust in the interstellar medium (ISM) to infer the properties of dust grains and characterize the metal and dust content of galaxies, down to low metallicity and intermediate redshift z. We provide metal…
We study the relationship between molecular gas and dust in the California Molecular Cloud over an unprecedented dynamic range of cloud depth (Av = 3 - 60 magnitudes). We compare deep Herschel-based measurements of dust extinction with…
We present the detection of dust depletion in Complex C, a massive, infalling, low-metallicity high-velocity cloud in the northern Galactic hemisphere that traces the ongoing accretion of gas onto the Milky Way. We analyze a very high…
The Earth is known to be depleted in volatile lithophile elements in a fashion that defies easy explanation. We resolve this anomaly with a model that combines the porosity of collisionally grown dust grains in protoplanetary disks with…
We review recent studies of organic molecule formation in dense molecular clouds and in comets. We summarise the known organic inventories of molecular clouds and recent comets, particularly Hale-Bopp. The principal chemical formation…
Distance estimates derived from spectroscopy or parallax have been unified by considering extinction by large grains. The addition of such a population of what is called Dark Dust to models of the diffuse interstellar medium is tested…
We compare the elemental depletions in the gas phase of the interstellar medium (ISM) with the elemental depletions in the rocky material of our Solar System. Our analysis finds a high degree of chemical complementarity: elements depleted…
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…
We use the C/N ratio as a monitor of the delivery of key ingredients of life to nascent terrestrial worlds. Total elemental C and N contents, and their ratio, are examined for the interstellar medium, comets, chondritic meteorites and…
X-ray absorption fine structure (XAFS) in the 0.2-2 keV band is a crucial component in multi-wavelength studies of dust mineralogy, size, and shape -- parameters that are necessary for interpreting astronomical observations and building…
We discuss new developments of interstellar chemistry, with particular emphasis on the carbon chemistry. We confirm that carbon chains and cycles are ubiquitous in the ISM and closely chemically related to ea ch other, and to carbon.…
Aluminum oxide (alumina, Al$_{2}$O$_{3}$) is a promising candidate as a primary dust condensate in the atmospheres of oxygen-rich evolved stars. Therefore, alumina \textit{seed} particles might trigger the onset of stellar dust formation…
Context. The chemistry of the diffuse interstellar medium rests upon three pillars: exothermic ion-neutral reactions (" cold chemistry "), endothermic neutral-neutral reactions with significant activation barriers (" warm chemistry "), and…
Molecular gas is the key ingredient of the star formation cycle, and tracing its dependencies on other galaxy properties is essential for understanding galaxy evolution. In this work, we explore the relation between the different phases of…
In spite of accounting for only a small fraction of the mass of the Interstellar Medium (ISM), dust plays a primary role in many physical and chemical processes in the Universe. It is the main driver of extinction of radiation in the…
We perform a homogeneous analysis of the Fe/Ni abundance ratio in eight Galactic planetary nebulae (PNe) and three Galactic H II regions that include the Orion nebula, where we study four nebular zones and one shocked region. We use [Fe…
Silicate minerals belong to the most abundant solids in space. Their formation becomes difficult at the transition from the oxygen rich chemistry of M-stars to the carbon rich chemistry of C-stars. In the intermediate type S-stars oxygen…