IR-Induced CO Photodesorption from Pure CO Ice and CO on Amorphous Solid Water
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View abstract on PubMed
Summary
This summary is machine-generated.Infrared photons can cause carbon monoxide (CO) to desorb from interstellar ice mantles. Energy transfer from water ice to CO is more efficient for CO desorption than direct CO excitation.
Area Of Science
- Astrochemistry
- Interstellar medium physics
- Surface science
Background
- Carbon monoxide (CO) is crucial in interstellar icy mantles, influencing complex organic molecule formation.
- Interstellar dust grains are exposed to radiation, linking solid-state and gas-phase chemistry.
- Infrared (IR) photons dominate radiation fields within dense molecular clouds, unlike UV photons.
Purpose Of The Study
- Investigate IR photon-induced desorption of CO from interstellar ice analogs.
- Compare CO desorption yields from CO/water ice to pure CO ice.
- Determine the role of energy transfer in IR-driven desorption.
Main Methods
- Deposition of CO onto amorphous solid water (ASW) to form a multilayer film.
- Irradiation of the ice film using the FELIX IR Free Electron Laser (FEL-2).
- Infrared spectroscopy and mass spectrometry to detect desorbing CO.
Main Results
- Exciting vibrational modes in the underlying ASW induced significant CO desorption.
- Direct excitation of CO's stretching mode resulted in inefficient CO desorption.
- Desorption efficiencies suggest efficient energy transfer within interstellar ices.
Conclusions
- Energy transfer within ices is a significant pathway for IR photon-induced desorption of volatile species like CO.
- This mechanism is important for understanding the link between solid-state ices and gas-phase molecules in dense clouds.
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