UV photodesorption of interstellar CO ice analogues: from subsurface excitation to surface desorption - Sorbonne Université Accéder directement au contenu
Article Dans Une Revue Physical Chemistry Chemical Physics Année : 2012

UV photodesorption of interstellar CO ice analogues: from subsurface excitation to surface desorption

Résumé

Carbon monoxide is after H 2 the most abundant molecule identified in the interstellar medium (ISM), and is used as a major tracer for the gas phase physical conditions. Accreted at the surface of water-rich icy grains, CO is considered as the starting point of a complex organic – presumably prebiotic – chemistry. Non-thermal desorption processes, and especially photodesorption by UV photons, are seen as the main cause that drives the gas-to-ice CO balance in the colder parts of the ISM. The process is known to be efficient and 10 wavelength-dependent, but, the underlying mechanism and the physical-chemical parameters governing the photodesorption are still largely unknown. Using monochromatized photons from a synchrotron beamline, we reveal that the molecular mechanism responsible for CO photoejection is an indirect, (sub)surface-located process. The local environment of the molecules plays a key role in the photodesorption efficiency, and is quenched by at least an order of magnitude for CO interacting with a water ice surface.
Fichier principal
Vignette du fichier
BERTIN_Accepted.pdf (332.39 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01620008 , version 1 (20-10-2017)

Identifiants

Citer

Mathieu Bertin, Edith C. Fayolle, Claire Romanzin, Karin I. Öberg, Xavier Michaut, et al.. UV photodesorption of interstellar CO ice analogues: from subsurface excitation to surface desorption. Physical Chemistry Chemical Physics, 2012, 14 (28), pp.9929-9935 ⟨10.1039/C2CP41177F⟩. ⟨hal-01620008⟩
344 Consultations
252 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More