Formation of complex organic molecules in ice mantles: An ab initio molecular dynamics study

We present a detailed simulation of a dust grain covered by a decamer of (CHOH)-ice-mantle, bombarded by an OH closed-shell molecule with kinetic energies from 10-22 eV. The chemical pathways are studied through Born-Oppenheimer (ab initio) molecular dynamics. The simulations show that methanol ice-...

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Detalles Bibliográficos
Autores: Inostroza, Natalia, Mardones, Diego, Cernicharo, José, Zinnecker, Hans, Ge, Jixing, Aria, Nelson, Fuentealba, Patricio, Cárdenas, Carlos
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/203899
Acceso en línea:http://hdl.handle.net/10261/203899
Access Level:acceso abierto
Palabra clave:Astrochemistry
Molecular processes
ISM: molecules
Dust
Extinction
Descripción
Sumario:We present a detailed simulation of a dust grain covered by a decamer of (CHOH)-ice-mantle, bombarded by an OH closed-shell molecule with kinetic energies from 10-22 eV. The chemical pathways are studied through Born-Oppenheimer (ab initio) molecular dynamics. The simulations show that methanol ice-mantles can be a key generator of complex organic molecules (COMs). We report the formation of COMs such as methylene glycol (CH(OH)) and the OCHOH radical, which have not been detected yet in the interstellar medium (ISM). We discuss the chemical formation of new species through the reaction of CHOH with the hydroxyl projectile. The dependence of the outcome on the kinetic energy of the projectile and the implications for the observation and detection of these molecules might explain why the methoxy radical (CH·) has been observed in a wider range of astrophysical environments than the hydroxymethyl (CH·) isomer. Because of the projectile kinetic energies required for these reactions to occur, we suggest that these processes are likely relevant in the production of COMs in photodissociation and shock regions produced by high-velocity jets and outflows from young stellar objects.