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| Titel |
Infrared spectra and thermodynamic properties of CH4/H2O ices |
| VerfasserIn |
O. Galvez, B. Mate, V. J. Herrero, R. M. Escribano |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250019959
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| Zusammenfassung |
| The coexistence of solid methane and water ice has been observed in outer Solar
System objects, in comets, and in interstellar ice mantles (1-3). CH4 is proposed to
be the starting point of rich organic chemistry in the astrophysical media. This
work presents an investigation on ice mixtures of methane and water. The samples
were analysed by infrared spectroscopy. In the range of temperatures spanned in
this study our investigations provide evidence of the existence of a distorted CH4
structure, characterized by an absorption band at 2900 cm-1, corresponding to the
symmetric stretch motion of the molecule, forbidden by symmetry in the pure solid. A
quantification of the amount of distorted CH4 trapped in the water ice structure, and its
dependence on the ice generation procedure has been conducted. The CH4:H2O
desorption energy has been determined. These and other findings will be discussed in the
presentation.
Boogert, A.C.A. “Interstellar Ices”. Astrophysics of Dust, ASP Conference
Series, Vol. 309, p. 547, 2004. A.N. Witt, G.C. Clayton.
Voss, L.F. et al., “Methane thermodynamics in nanoporous ice: A new methane
reservoir on Titan.” J. Geophys. Res., 112, E05002, doi: 10.1029/2006JE002768,
2007. |
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