The desorption of H2CO from interstellar grains analogues
| Autor: | Patrice Theulé, Grégoire Danger, Fabrice Duvernay, F. Mispelaer, Jennifer A. Noble, Thierry Chiavassa, E. Congiu, François Dulieu |
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| Přispěvatelé: | Institute of Biomedical Engineering [Oxford] (IBME), University of Oxford [Oxford], Physique des interactions ioniques et moléculaires (PIIM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), LERMA Cergy (LERMA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire de Physique Moleculaire pour l'Atmosphere et l'Astrophysique (LPMAA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), University of Oxford, Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Physics
Astrochemistry Thermal desorption spectroscopy Analytical chemistry Thermal desorption Astronomy and Astrophysics Context (language use) 02 engineering and technology Astrophysics 021001 nanoscience & nanotechnology Mass spectrometry 7. Clean energy 01 natural sciences Soft laser desorption 13. Climate action Space and Planetary Science [SDU]Sciences of the Universe [physics] Field desorption Desorption 0103 physical sciences [CHIM]Chemical Sciences Atomic physics 0210 nano-technology 010303 astronomy & astrophysics ComputingMilieux_MISCELLANEOUS |
| Zdroj: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2012, 543, pp.A5. ⟨10.1051/0004-6361/201219437⟩ Astronomy and Astrophysics-A&A, 2012, 543, pp.A5. ⟨10.1051/0004-6361/201219437⟩ |
| ISSN: | 0004-6361 |
| DOI: | 10.1051/0004-6361/201219437⟩ |
| Popis: | WOS:000306597200005; International audience; Context. Much of the formaldehyde (H2CO) is formed from the hydrogenation of CO on interstellar dust grains, and is released in the gas phase in hot core regions. Radio-astronomical observations in these regions are directly related to its desorption from grains. Aims. We study experimentally the thermal desorption of H2CO from bare silicate surfaces, from water ice surfaces and from bulk water ice in order to model its desorption from interstellar grains. Methods. Temperature-programmed desorption experiments, monitored by mass spectrometry, and Fourier transform infrared spectroscopy are performed in the laboratory to determine the thermal desorption energies in: (i.) the multilayer regime where H2CO is bound to other H2CO molecules; (ii.) the submonolayer regime where H2CO is bound on top of a water ice surface; (iii.) the mixed submonolayer regime where H2CO is bound to a silicate surface; and (iv.) the multilayer regime in water ice, where H2CO is embedded within a H2O matrix. Results. In the submonolayer regime, we find the zeroth-order desorption kinetic parameters nu(0) = 10(28) mol cm(-2) s(-1) and E = 31.0 +/- 0.9 kJmol(-1) for desorption from an olivine surface. The zeroth-order desorption kinetic parameters are nu(0) = 10(28) mol cm(-2) s(-1) and E = 27.1 +/- 0.5 kJmol(-1) for desorption from a water ice surface in the submonolayer regime. In a H2CO:H2O mixture, the desorption is in competition with the H2CO + H2O reaction, which produces polyoxymethylene, the polymer of H2CO. This polymerization reaction prevents the volcano desorption and co-desorption from happening. Conclusions. H2CO is only desorbed from interstellar ices via a dominant sub-monolayer desorption process (E = 27.1 +/- 0.5 kJmol-1). The H2CO which has not desorbed during this sub-monolayer desorption polymerises upon reaction with H2O, and does not desorb as H2CO at higher temperature. |
| Databáze: | OpenAIRE |
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