Related papers: Experimental evidence for water formation via ozon…
[Abridged] Observations of protoplanetary disks suggest that they are depleted in gas-phase CO. It has been posed that gas-phase CO is chemically consumed and converted into less volatile species through gas-grain processes. Observations of…
We present the modeling results of deuterium fractionation of water ice, H2, and the primary deuterium isotopologues of H3+ adopting physical conditions associated with the star and planet formation process. We calculated the deuterium…
The energy to desorb atomic oxygen from an interstellar dust grain surface, $E_{\rm des}$, is an important controlling parameter in gas-grain models; its value impacts the temperature range over which oxygen resides on a dust grain.…
Recent laboratory experiments on interstellar dust analogues have shown that H_2 formation on dust grain surfaces is efficient in a range of grain temperatures below 20 K. These results indicate that surface processes may account for the…
Because chemical reactions on/in cosmic ice dust grains covered by amorphous solid water (ASW) play important roles in generating a variety of molecules, many experimental and theoretical studies have focused on the chemical processes…
Context. Millimetric observations have measured high degrees of molecular deuteration in several species seen around low-mass protostars. The Herschel Space Telescope, launched in 2009, is now providing new measures of the deuterium…
Simple and complex organic molecules (COMs) are observed along different phases of star and planet formation and have been successfully identified in prestellar environments such as dark and translucent clouds. Yet the picture of organic…
There has always been a great deal of interest in the formation of H2 as well as in the binding energy released upon its formation on the surface of dust grains. The present work aims at collecting experimental evidence for how the bond…
Understanding the formation of molecules under conditions relevant to interstellar chemistry is fundamental to characterize the chemical evolution of the universe. Using reactive molecular dynamics simulations with model-based or…
We re-examine the constraints provided by Herschel Space Observatory data regarding cold water emission from protoplanetary disks. Previous disk models that were used to interpret observed water emission concluded that oxygen (O/H) is…
The formation of H2 and HD molecules on interstellar dust grains is studied using rate equation and master equation models. Rate equations are used in the analysis of laboratory experiments which examine the formation of molecular hydrogen…
Understanding the history and evolution of small bodies, such as dust grains and comets, in planet-forming disks is very important to reveal the architectural laws responsible for the creation of planetary systems. These small bodies in…
The Herschel Space Observatory's recent detections of water vapor in the cold, dense cloud L1544 allow a direct comparison between observations and chemical models for oxygen species in conditions just before star formation. We explain a…
Zare and co-workers have recently claimed that hydrogen peroxide is spontaneously generated on the air-water interface of sprayed microdroplets, i.e., that H2O2 forms without an external energy source or co-reactant or catalyst.…
Recent interferometer observations have found that the D2O/HDO abundance ratio is higher than that of HDO/H2O by about one order of magnitude in the vicinity of low-mass protostar NGC 1333-IRAS 2A, where water ice has sublimated. Previous…
Chemical processes on the surface of icy grains play an important role in the chemical evolution in molecular clouds. In particular, reactions involving non-energetic hydrogen atoms accreted from the gaseous phase have been extensively…
Methane is one of the simplest stable molecules that is both abundant and widely distributed across space. It is thought to have partial origin from interstellar molecular clouds, which are near the beginning of the star formation cycle.…
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…
Water (H2O) ice is an important solid constituent of many astrophysical environments. To comprehend the role of such ices in the chemistry and evolution of dense molecular clouds and comets, it is necessary to understand the freeze-out,…
Aqueous radiation chemistry emerges through ultrafast proton transfer and ion-radical formation with unexplored energy-redistribution dynamics steering the subsequent reactions. We performed time-resolved disruptive probing on pure water…