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Related papers: Tunneling Rate Constants for H2CO+H on Amorphous S…

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In the interstellar cold gas, the chemistry of formaldehyde (H$_2$CO) can be essential to explain the formation of complex organic molecules. On this matter, the massive and energetic protostellar object G331 is still unexplored and, hence,…

Astrophysics of Galaxies · Physics 2023-08-09 Edgar Mendoza , Miguel Carvajal , Manuel Merello , Leonardo Bronfman , Heloisa M. Boechat-Roberty

Hydrogen addition and abstraction reactions play an important role as surface reactions in the buildup of complex organic molecules in the dense interstellar medium. Addition reactions allow unsaturated bonds to be fully hydrogenated, while…

Astrophysics of Galaxies · Physics 2018-09-19 V. Zaverkin , T. Lamberts , M. N. Markmeyer , J. Kästner

We investigated the behavior of H$_2$, main constituent of the gas phase in dense clouds, after collision with amorphous solid water (ASW) surfaces, one of the most abundant chemical species of interstellar ices. We developed a general…

Chemical Physics · Physics 2020-03-20 G. Molpeceres , J. Kästner

Solid state astrochemical reaction pathways have the potential to link the formation of small nitrogen-bearing species, like NH3 and HNCO, and prebiotic molecules, specifically amino acids. To date, the chemical origin of such small…

Astrophysics of Galaxies · Physics 2017-05-26 Gleb Fedoseev , Sergio Ioppolo , Dongfeng Zhao , Thanja Lamberts , Harold Linnartz

Glycoaldehyde, ethylene glycol, and methyl formate are complex organic molecules that have been observed in dark molecular clouds. Because there is no efficient gas-phase route to produce these species, it is expected that a low-temperature…

Solar and Stellar Astrophysics · Physics 2020-02-12 M. A. J. Simons , T. Lamberts , H. M. Cuppen

Water is abundantly present in the Universe. It is the main component of interstellar ice mantles and a key ingredient for life. Water in space is mainly formed through surface reactions. Three formation routes have been proposed in the…

Solar and Stellar Astrophysics · Physics 2017-08-23 H. M. Cuppen , S. Ioppolo , C. Romanzin , H. Linnartz

Hydrogen, being the most abundant element, is the driver of many if not most reactions occurring on interstellar dust grains. In hydrogen atom addition reactions, the rate is usually determined by the surface kinetics of the hydrogen atom…

Instrumentation and Methods for Astrophysics · Physics 2017-12-27 Jiao He , Shahnewaj M. Emtiaz , Gianfranco Vidali

Context. In dense clouds, hydrogenation reactions on icy dust grains are key in the formation of molecules, like formaldehyde, methanol, and complex organic molecules (COMs). These species form through the sequential hydrogenation of CO…

Solar and Stellar Astrophysics · Physics 2018-09-28 K. -J. Chuang , G. Fedoseev , D. Qasim , S. Ioppolo , E. F. van Dishoeck , H. Linnartz

In the quest to understand the formation of the building blocks of life, amorphous solid water (ASW) is one of the most widely studied molecular systems. Indeed, ASW is ubiquitous in the cold interstellar medium (ISM), where ASW-coated dust…

Chemical Physics · Physics 2014-02-17 Jennifer A Noble , Céline Martin , Helen J. Fraser , Pascale Roubin , Stéphane Coussan

Using arguments parallel to those used in support of using H2CO as a sensitive probe of temperature and density in molecular clouds, we measured the J=7-6 and J=10-9 transitions of thioformaldehyde (H2CS) in several hot core sources. The…

Astrophysics of Galaxies · Physics 2009-07-24 Alwyn Wootten , Jeffrey G. Mangum

We present a combined experimental and theoretical study focussing on the quantum tunneling of atoms in the reaction between CH4 and OH. The importance of this reaction pathway is derived by investigating isotope substituted analogs.…

Astrophysics of Galaxies · Physics 2017-03-15 Thanja Lamberts , Gleb Fedoseev , Johannes Kästner , Sergio Ioppolo , Harold Linnartz

The interpretation of water line emission from existing observations and future HIFI/Herschel data requires a detailed knowledge of collisional rate coefficients. Among all relevant collisional mechanisms, the rotational (de)excitation of…

Astrophysics · Physics 2009-11-13 A. Faure , N. Crimier , C. Ceccarelli , P. Valiron , L. Wiesenfeld , M. -L. Dubernet

CO2 ice is one of the most abundant components in ice-coated interstellar ices besides H2O and CO, but the most favorable path to CO2 ice is still unclear. Molecular dynamics calculations on the ultraviolet photodissociation of different…

Chemical Physics · Physics 2015-06-17 Carina Arasa , Marc C. van Hemert , Ewine F. van Dishoeck , Geert-Jan Kroes

Understanding water deuterium fractionation is important for constraining the mechanisms of water formation in interstellar clouds. Observations of HDO and H$_2^{18}$O transitions were carried out towards the high-mass star-forming region…

The radicals HCO and CH$_3$ on carbon monoxide ice surfaces were simulated using density functional theory. Their binding energy on amorphous CO ice shows broad distributions, with approximative average values of 500 K for HCO and 200 K for…

Astrophysics of Galaxies · Physics 2019-04-16 Thanja Lamberts , Max N. Markmeyer , Florian J. Kolb , Johannes Kästner

We have developed a model for molecular hydrogen formation under astrophysically relevant conditions. This model takes fully into account the presence of both physisorbed and chemisorbed sites on the surface, allows quantum mechanical…

Astrophysics · Physics 2009-11-07 S. Cazaux , A. G. G. M. Tielens

Using infrared spectroscopy combined with ab initio methods we study reactions of H$_2$O and CO inside the confined spaces of Zn-MOF-74 channels. Our results show that, once the water dissociation reaction H$_2$O$\;\rightarrow\;$OH+H takes…

Chemical Physics · Physics 2016-09-06 S. Zuluaga , E. M. A. Fuentes-Fernandez , K. Tan , C. A. Arter , J. Li , I. J. Chabal , T. Thonhauser

The rates of numerous activated reactions between neutral species increase at low temperatures through quantum mechanical tunneling of light hydrogen atoms. Although tunneling processes involving molecules or heavy atoms are well known in…

Water-solid interfaces pervade the natural environment and modern technology. On some surfaces, water-water interactions induce the formation of partially dissociated interfacial layers; understanding why is important to model processes in…