| People | Locations | Statistics |
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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Herrero, Victor
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (3/3 displayed)
- 2024Experimental Phase Function and Degree of Linear Polarization of Light Scattered by Hydrogenated Amorphous Carbon Circumstellar Dust Analogscitations
- 2019Desorption of volatile molecules from the surface of interstellar carbonaceous dust analogs
- 2018Stability of CH<sub>3</sub>NCO in Astronomical Ices under Energetic Processing: A Laboratory Studycitations
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article
Stability of CH<sub>3</sub>NCO in Astronomical Ices under Energetic Processing: A Laboratory Study
Abstract
<jats:title>Abstract</jats:title><jats:p>Methyl isocyanate (CH<jats:sub>3</jats:sub>NCO) was recently found in hot cores and suggested to exist on comet 67P/CG. The incorporation of this molecule into astrochemical networks requires data on its formation and destruction. In this work, ices of pure CH<jats:sub>3</jats:sub>NCO and of CH<jats:sub>3</jats:sub>NCO(4%–5%)/H<jats:sub>2</jats:sub>O mixtures deposited at 20 K were irradiated with a UV D<jats:sub>2</jats:sub> lamp (120–400 nm) and bombarded by 5 keV electrons to mimic the secondary electrons produced by cosmic rays (CRs). The destruction of CH<jats:sub>3</jats:sub>NCO was studied using IR spectroscopy. After processing, the <jats:italic>ν</jats:italic><jats:sub>a</jats:sub>–NCO band of CH<jats:sub>3</jats:sub>NCO disappeared and IR bands corresponding to CO, CO<jats:sub>2</jats:sub>, OCN<jats:sup>−</jats:sup>, and HCN/CN<jats:sup>−</jats:sup> appeared instead. The products of photon and electron processing were very similar. Destruction cross sections and half-life doses were derived from the measurements. Water ice provides a good shield against UV irradiation (half-life dose of ∼64 eV molecule<jats:sup>−1</jats:sup> for CH<jats:sub>3</jats:sub>NCO in water ice), but is not so good against high-energy electrons (half-life dose ∼18 eV molecule<jats:sup>−1</jats:sup>). It was also found that CH<jats:sub>3</jats:sub>NCO does not react with H<jats:sub>2</jats:sub>O over the temperature range 20–200 K. These results indicate that hypothetical CH<jats:sub>3</jats:sub>NCO in the ices of dense clouds should be stable against UV photons and relatively stable against CRs over the lifetime of a cloud (∼10<jats:sup>7</jats:sup> yr), and could sublime in the hot core phase. On the surface of a Kuiper Belt object (the original location of comet 67P/CG) the molecule would be swiftly destroyed, by both photons and CRs, but embedded below just 10 <jats:italic>μ</jats:italic>m of water ice, the molecule could survive for ∼10<jats:sup>9</jats:sup> yr.</jats:p>