1. Hydroxylated Mg-rich Amorphous Silicates: A New Component of the 3.2 μ m Absorption Band of Comet 67P/Churyumov–Gerasimenko
- Author
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Mennella, V., Ciarniello, M., Raponi, A., Capaccioni, F., Filacchione, G., Suhasaria, T., Popa, C., Kappel, D., Moroz, L., Vinogradoff, V., Pommerol, A., Rousseau, Batiste, Istiqomah, I., Quirico, E, Beck, P, Bockelée-Morvan, D., Carlson, R., Pilorget, C., INAF—Osservatorio Astronomico di Capodimonte, IAPS–INAF, Istituto di Astrofisica e Planetologia Spaziali, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), and ITA
- Subjects
010504 meteorology & atmospheric sciences ,Comet ,Analytical chemistry ,Infrared spectroscopy ,spectroscopic ,01 natural sciences ,general -methods ,Spectral line ,0103 physical sciences ,atomic processestechniques ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Cosmic dust ,Physics ,Alkaline earth metal ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,astrochemistry ,astrochemistry -comets ,Astronomy and Astrophysics ,Amorphous solid ,13. Climate action ,Space and Planetary Science ,Absorption band ,[SDU]Sciences of the Universe [physics] ,techniques:spectroscopic ,Absorption (chemistry) ,comets:general ,laboratory ,methods:laboratory:atomicprocesses - Abstract
International audience; The VIRTIS imaging spectrometer on board Rosetta has shown that the nucleus surface of comet 67P/ Churyumov-Gerasimenko (67P/CG) is characterized by a broad absorption band at around 3.2 μm. The feature is ubiquitous across the surface and its attribution to (a) specific material(s) has been challenging. In the present Letter, we report an experimental investigation showing that the interaction of hydrogen atoms with Mg-rich amorphous silicates determines the formation of hydroxyl groups. The resulting IR spectrum exhibits a broad feature around 3.2 μm similar to that of comet 67P/CG. Hapke's radiative transfer model was employed to estimate an upper limit contribution of 65% of hydroxylated silicates to the observed cometary band intensity. The presence of a hydroxylated fraction in silicates on the cometary surface would represent an evolutionary link between primitive objects of the solar system and dust in the interstellar medium (ISM), where silicate grains can be hydroxylated after having interacted with hydrogen atoms. This link is consistent with the detection of the aliphatic organics in 67P/CG that also originate in the ISM.
- Published
- 2020
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