Modelling methanol and hydride formation in the JWST Ice Age era
[Context]: Recent JWST observations have measured the ice chemical composition toward two highly-extinguished background stars, NIR38 and J110621, in the Chamaeleon I molecular cloud. The observed excess of extinction on the long-wavelength side of the H2O ice band at 3 µm has been attributed to a m...
| Autores: | , , , , , , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión enviada para evaluación y publicación |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/382957 |
| Acceso en línea: | http://hdl.handle.net/10261/382957 |
| Access Level: | acceso abierto |
| Palabra clave: | (ISM:) dust, extinction ISM: molecules ISM: clouds |
| Sumario: | [Context]: Recent JWST observations have measured the ice chemical composition toward two highly-extinguished background stars, NIR38 and J110621, in the Chamaeleon I molecular cloud. The observed excess of extinction on the long-wavelength side of the H2O ice band at 3 µm has been attributed to a mixture of CH3OH with ammonia hydrates (NH3·H2O), which suggests that CH3OH ice in this cloud could have formed in a water-rich environment with little CO depletion. Laboratory experiments and quantum chemical calculations suggest that CH3OH could form via the grain surface reactions CH3 + OH and/or C + H2O in water-rich ices. However, no dedicated chemical modelling has been carried out thus far to test their efficiency. In addition, it remains unexplored how the efficiencies of the proposed mechanisms depend on the astrochemical code employed. |
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