Article Dans Une Revue The Astrophysical Journal Letters Année : 2020

Hydroxylated Mg-rich Amorphous Silicates: A New Component of the 3.2 μ m Absorption Band of Comet 67P/Churyumov–Gerasimenko

Résumé

The VIRTIS imaging spectrometer aboard 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 paper, 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.

Fichier principal
Vignette du fichier
Manuscript_Mennella_revision.pdf (1.43 Mo) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)
Licence

Dates et versions

hal-02996616 , version 2 (30-11-2020)
hal-02996616 , version 1 (10-12-2020)

Licence

Identifiants

Citer

V. Mennella, M. Ciarniello, A. Raponi, F. Capaccioni, G. Filacchione, et al.. Hydroxylated Mg-rich Amorphous Silicates: A New Component of the 3.2 μ m Absorption Band of Comet 67P/Churyumov–Gerasimenko. The Astrophysical Journal Letters, 2020, 897 (2), pp.L37. ⟨10.3847/2041-8213/ab919e⟩. ⟨hal-02996616v2⟩
182 Consultations
246 Téléchargements

Altmetric

Partager

  • More