Related papers: Photodesorption of water ice: a molecular dynamics…
Under cold conditions in dense cores, gas-phase molecules and atoms are depleted from the gas-phase to the surface of interstellar grains. Considering the time scales and physical conditions within these cores, a portion of these molecules…
We present the combined 2.5$-$30$\mu$m spectra of four protostars acquired with the infrared camera and the infrared spectrograph on board the AKARI and Spitzer space telescopes, respectively. To analyze the ice absorption features in the…
At the low temperatures of interstellar dust grains, it is well established that surface chemistry proceeds via diffusive mechanisms of H atoms weakly bound (physisorbed) to the surface. Until recently, however, it was unknown whether atoms…
We study the H2O chemistry in star-forming environments under the influence of a central X-ray source and a central far ultraviolet (FUV) radiation field. The gas-phase water chemistry is modeled as a function of time, hydrogen density and…
While the small sticking coefficient for molecular hydrogen on the Si(001) surface apparently requires a large energy barrier of adsorption, no such barrier is observed in desorption experiments. We have calculated the potential-energy…
The spectrometers onboard the Infrared Telescope in Space (IRTS) reveal water vapor absorption in early M-type stars, as early as M2. Previous observations detected H_2O vapor absorption only in stars later than M6, with the exception of…
We have investigated the time scale for formation of molecular clouds by examining the conversion of HI to H2 using a time-dependent model. H2 formation on dust grains and cosmic ray and photo destruction are included in one-dimensional…
Water adsorption on silicate surfaces is a critical yet poorly understood process relevant to, e.g., mineral weathering and cement hydration. This study investigates the structure of water overlayers on a model calcium silicate, the…
Photodissociation of 14N2 and 14N15N occurs in interstellar clouds, circumstellar envelopes, protoplanetary discs, and other environments due to UV radiation from stellar sources and the presence of cosmic rays. This source of N atoms…
First-principles calculations based on density functional theory and the pseudopotential method have been used to investigate the energetics of H$_2$O adsorption on the (110) surface of TiO$_2$ and SnO$_2$. Full relaxation of all atomic…
We report the detection of absorption lines by the reactive ions OH+, H2O+ and H3O+ along the line of sight to the submillimeter continuum source G10.6$-$0.4 (W31C). We used the Herschel HIFI instrument in dual beam switch mode to observe…
Molecular beam experiments that use low-temperature bolometers as (energy-) detectors are well suited to the study of physisorption and recombination of hydrogen on low-temperature surfaces. Experiments where this technique is combined with…
The need to characterize ices coating dust grains in dense interstellar clouds arises from the importance of ice morphology in facilitating the diffusion and storage of radicals and reaction products in ices, a well-known place for the…
Interstellar ices are mainly composed of amorphous solid water (ASW) containing small amounts of hypervolatiles, such as O2, whose diffusion-limited reactions play a key role in space chemistry. Although O2 is an important precursor…
The absolute photodetachment cross section of OH- anions at a rotational and translational temperature of 170K is determined by measuring the detachment-induced decay rate of the anions in a multipole radio-frequency ion trap. In comparison…
Study of interstellar elemental depletion poses an important problem in the interstellar matter that at least a quarter of the total oxygen ($\sim 160$ ppm relative to hydrogen) is not accounted for in any known form of oxygen in the…
Aims. Formamide (HCONH2) is the simplest molecule containing the peptide bond first detected in the gas phase in Orion-KL and SgrB2. In recent years, it has been observed in high temperature regions such as hot corinos, where thermal…
The deuterium fractionation of water can serve as a tracer for the chemical and physical evolution of water during star formation and can constrain the origin of water in Solar System bodies. We determine the HDO/H$_2$O ratio in the inner…
Sulfur dioxide (SO2) is a sulfur-containing molecule expected to exist as a solid in the interstellar medium (ISM). In this study, we performed laboratory experiments and computational analyses on the surface reactions of solid SO2 with…
We investigate the variation of the oscillation frequency of the Mg$^{2+}$ and O$^{2-}$ ions in the magnesium oxide lattice due to the interactions of the surface with water monolayers by means of Low Energy Electron Diffraction. Our key…