相关论文: Molecular Hydrogen Formation on Amorphous Silicate…
Adhesion forces between submicrometer-sized silicate grains play a crucial role in the formation of silicate dust agglomerates, rocky planetesimals, and terrestrial planets. The surface energy of silicate dust particles is the key to their…
Molecular hydrogen is the most abundant molecule in the universe. It is the first one to form and survive photo-dissociation in tenuous environments. Its formation involves catalytic reactions on the surface of interstellar grains. The…
Recent experimental results on the formation of molecular hydrogen on astrophysically relevant surfaces under conditions similar to those encountered in the interstellar medium provided useful quantitative information about these processes.…
We study the formation of molecular hydrogen on dust grain surfaces and apply our results to the high redshift universe. We find that a range of physical parameters, in particular dust temperature and gas temperature, but not so much dust…
Aims. Interstellar dust grains, because of their catalytic properties, are crucial to the formation of H2, the most abundant molecule in the Universe. The formation of molecular hydrogen strongly depends on the ability of H atoms to stick…
Molecular hydrogen (H$_2$) plays a critical role in astrophysical processes from galaxy evolution to the formation of planets. While the dominant formation channel in the interstellar medium is considered as dust-catalyzed H$_2$ formation,…
The recombination of hydrogen in the interstellar medium, taking place on surfaces of microscopic dust grains, is an essential process in the evolution of chemical complexity in interstellar clouds. The H_2 formation process has been…
Molecular hydrogen is the most abundant molecular species in the Universe. While no doubts exist that it is mainly formed on the interstellar dust grain surfaces, many details of this process remain poorly known. In this work, we focus on…
We construct a theoretical model for low-temperature crystallization of amorphous silicate grains induced by exothermic chemical reactions. As a first step, the model is applied to the annealing experiments, in which the samples are (1)…
A model is proposed for the formation of water ice mantles on grains in interstellar clouds. This occurs by direct accretion of monomers from the gas, be they formed by gas or surface reactions. The model predicts the existence of a…
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…
While it is well recognized that interstellar grains are made of amorphous silicates and some form of carbonaceous materials, it remains debated regarding what exact chemical and physical form the carbonaceous component takes. Contemporary…
Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. Especially, saturated, hydrogen-rich molecules are formed through surface chemistry.…
Lyman and Werner band absorption features from interstellar molecular hydrogen in rotational levels J = 0, 1, 2, 3 and 5 were observed in the spectrum of zeta Ori A by the Interstellar Medium Absorption Profile Spectrograph (IMAPS). Most of…
The condensation of complex silicates with pyroxene and olivine composition at conditions prevailing in molecular clouds has been experimentally studied. For this purpose, molecular species comprising refractory elements were forced to…
The properties of the first-discovered interstellar object (ISO), 1I/2017 (`Oumuamua), differ from both Solar System asteroids and comets, casting doubt on a protoplanetary disk origin. In this study, we investigate the possibility that it…
The morphology of water ice in the interstellar medium is still an open question. Although accretion of gaseous water could not be the only possible origin of the observed icy mantles covering dust grains in cold molecular clouds, it is…
The formation and growth of refractory matter on pre-existing interstellar dust grain surfaces was studied experimentally by annealing neon-ice matrices in which potential precursors of silicate grains (Mg and Fe atoms, SiO and SiO$_2$…
A possible formation mechanism of hydrogen molecules on a galactic scale is examined. We are interested especially in the role of hydrogen molecules for formation and evolution of primordial galaxies. Then, formation process of hydrogen…
Hydroxylamine (NH2OH) is one of the potential precursors of complex pre-biotic species in space. Here we present a detailed experimental study of hydroxylamine formation through nitric oxide (NO) surface hydrogenation for astronomically…