Desorption of N2, CO, CH4 and CO2 from interstellar carbonaceous dust analogues
| Autor: | Isabel Tanarro, Belén Maté, Miguel Jiménez-Redondo, Víctor J. Herrero, Ramón J. Peláez |
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| Přispěvatelé: | Ministerio de Economía y Competitividad (España), European Commission |
| Rok vydání: | 2019 |
| Předmět: |
Physics
ISM: molecules Astrochemistry Methods: laboratory: molecular Molecular data laboratory: molecular [Methods] Astronomy and Astrophysics 010402 general chemistry Photochemistry evolution [ISM] 01 natural sciences Methods: laboratory: solid state molecules. [ISM] 0104 chemical sciences ISM: evolution laboratory: solid state [Methods] Space and Planetary Science Desorption 0103 physical sciences 010303 astronomy & astrophysics |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | 12 pags., 8 figs., 3 tabs. The interaction of volatile species with carbonaceous interstellar dust analogues is of relevance in the chemistry and physics of dense clouds in the interstellar medium. Two deposits of hydrogenated amorphous carbon (HAC), with different morphologies and aromatic versus aliphatic ratio in their structure, have been grown to model interstellar dust. The interaction of N2, CO, CH4, and CO2 with these two surfaces has been investigated using thermal programmed desorption (TPD). Desorption energy distributions were obtained by analysing TPD spectra for one monolayer coverage with the Polanyi–Wigner equation. The desorption energies found in this work for N2, CO, and CH4 are larger by 10–20 per cent than those reported in the literature for siliceous or amorphous solid water surfaces. Moreover, the experiments suggest that the interaction of the volatiles with the aromatic substructure of HAC is stronger than that with the aliphatic part. Desorption of CO2 from the HAC surfaces follows zero-order kinetics, reflecting the predominance of CO2–CO2 interactions. A model simulation of the heating of cold cloud cores shows that the volatiles considered in this work would desorb sequentially from carbonaceous dust surfaces with desorption times ranging from hundreds to tens of thousands of years, depending on the molecule and on the mass of the core This work was funded by the Ministerio de Economia y Competitividad (MINECO) of Spain under grant FIS2016-77726-C3-1-P and by the European Union under grant ERC-2013-Syg-210656- NANOCOSMOS |
| Databáze: | OpenAIRE |
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