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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Ion irradiation of pure and amorphous CH4 ice relevant for astrophysical environments

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Autor(es):
Vasconcelos, F. A. ; Pilling, S. ; Rocha, W. R. M. ; Rothard, H. ; Boduch, P. ; Ding, J. J.
Número total de Autores: 6
Tipo de documento: Artigo Científico
Fonte: Physical Chemistry Chemical Physics; v. 19, n. 20, p. 12845-12856, MAY 28 2017.
Citações Web of Science: 13
Resumo

This work presents a physicochemical study of frozen amorphous methane (at 16 K) under bombardment by medium-mass ions (15.7 MeV O-16(5+)) with implications for icy bodies in the outer Solar System exposed to the action of cosmic rays and energetic particles. The experiment was performed at the Grand Accelerateur National d'Ions Lourds (GANIL) located in Caen, France. The results demonstrate that irradiation of CH4-containing ices by swift medium mass ions with delivered energy covering both stopping power regimes until its implantation on ice (i.e. electronic and nuclear) leads to the production of many hydrocarbons, such as C2H2, C2H4, C2H6, and C3H8 (the most abundant daughter species produced). Values for the effective dissociation cross section of CH4 and the average value for the effective formation cross-sections of its daughter species were about 10(-14) cm(2) and 10(-15) cm(2), respectively. The half-life of methane ice in the presence of swift medium mass ions extrapolated to some outer Solar System environments is estimated to be around 10(6) years. The measured sputtering yield of methane due to incoming swift ions was about 7.30 x 105 molecules per impact. Such parameters can be used as models to estimate the amount of CH4 and other molecular species desorbed from the icy surfaces that are constantly being incorporated to the gaseous atmosphere in the vicinity of these outer Solar System bodies due to the presence of energetic particles and cosmic rays. (AU)

Processo FAPESP: 15/10492-3 - Estudo da evolução química de gelos astrofísicos na vizinhança de objetos estelares jovens empregando dados experimentais no infravermelho e modelagem computacional
Beneficiário:Will Robson Monteiro Rocha
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 09/18304-0 - Síntese e degradação de espécies moleculares pré-bióticas em atmosferas planetárias, cometas e gelos interestelares simulados
Beneficiário:Sergio Pilling Guapyassu de Oliveira
Linha de fomento: Auxílio à Pesquisa - Apoio a Jovens Pesquisadores
Processo FAPESP: 13/07657-5 - Modelagem computacional do ambiente circum-estelar de protoestrelas empregando dados de gelos bombardeados por raios cósmicos simulados em laboratório
Beneficiário:Will Robson Monteiro Rocha
Linha de fomento: Bolsas no Brasil - Doutorado