Cosmic ray sputtering yield of interstellar ice mantles: CO and CO2 ice thickness dependence

Abstract

Cosmic-ray-induced sputtering is one of the important desorption mechanisms at work in astrophysical environments. The chemical evolution observed in high-density regions, from dense clouds to protoplanetary disks, and the release of species condensed on dust grains, is one key parameter to be taken into account in interpretations of both observations and models. This study is part of an ongoing systematic experimental determination of the parameters to consider in astrophysical cosmic ray sputtering. As was already done for water ice, we investigated the sputtering yield as a function of ice mantle thickness for the two next most abundant species of ice mantles, carbon monoxide and carbon dioxide, which were exposed to several ion beams to explore the dependence with deposited energy. These ice sputtering yields are constant for thick films. It decreases rapidly for thin ice films when reaching the impinging ion sputtering desorption depth. An ice mantle thickness dependence constraint can be implemented in the astrophysical modelling of the sputtering process, in particular close to the onset of ice mantle formation at low visual extinctions.

To appear in Astronomy & Astrophysics

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Cited by in corpus (6)

• Efficiency of non-thermal desorptions in cold-core conditions. Testing the sputtering of grain mantles induced by cosmic rays
• Laboratory and Computational Studies of Interstellar Ices
• Density and infrared band strength of interstellar carbon monoxide (CO) ice analogues
• Ice mantles on dust grains: dramatic variation of thickness with grain size
• Bombardment of CO ice by cosmic rays: I. Experimental insights into the microphysics of molecule destruction and sputtering
• The Cosmic-Ray Induced Sputtering Process On Icy Grains