Microwave spectra of the leading and trailing hemispheres of Iapetus - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue Icarus Année : 2024

Microwave spectra of the leading and trailing hemispheres of Iapetus

Alice Le Gall

Résumé

The leading hemisphere of Saturn’s synchronous moon Iapetus is covered by a low-albedo material, contrasting with its bright trailing hemisphere. This dichotomy is also apparent in radar and microwave radiometry observations, which are sensitive to the properties of the near subsurface. To better understand the regional properties of Iapetus and their variations with depth, we assemble the microwave spectra of its leading and trailing hemispheres. Pre-existing data are combined with new millimetric and centimetric observations acquired with the IRAM 30-meter dish, IRAM NOEMA interferometer, and VLA interferometer. These data, interpreted with the help of a model with vertically uniform thermal properties, reveal complex variations in structure and/or composition with depth on the leading side. Meanwhile, the trailing side emissivity is found to be especially low at all observed frequencies, indicating efficient scattering processes on subsurface structures, as observed on Saturn’s other icy moons. We also report the first observations of Saturn’s retrograde moon Phoebe at these frequencies, which has an emissivity higher than that of the trailing hemisphere of Iapetus and similar to its dark leading side, consistent with the theory that Phoebe is the source of the dark material on Iapetus.
Fichier sous embargo
Fichier sous embargo
0 2 15
Année Mois Jours
Avant la publication
vendredi 12 juillet 2024
Fichier sous embargo
vendredi 12 juillet 2024
Connectez-vous pour demander l'accès au fichier

Dates et versions

insu-04390930 , version 1 (12-01-2024)

Identifiants

Citer

Léa Bonnefoy, Emmanuel Lellouch, Alice Le Gall, Jean-François Lestrade, Raphaël Moreno, et al.. Microwave spectra of the leading and trailing hemispheres of Iapetus. Icarus, 2024, 411, ⟨10.1016/j.icarus.2024.115950⟩. ⟨insu-04390930⟩
39 Consultations
1 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More