Evidence for depletion of heavy silicon isotopes at comet 67P/Churyumov-Gerasimenko - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue Astronomy and Astrophysics - A&A Année : 2017

Evidence for depletion of heavy silicon isotopes at comet 67P/Churyumov-Gerasimenko

Martin Rubin
  • Fonction : Auteur
  • PersonId : 986621
Jean-Jacques Berthelier
  • Fonction : Auteur
  • PersonId : 968600
Ursina Calmonte
  • Fonction : Auteur
  • PersonId : 994259
Léna Le Roy

Résumé

The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) was designed to measure the composition of the gas in the coma of comet 67P/Churyumov-Gerasimenko, the target of the European Space Agency’s Rosetta mission. In addition to the volatiles, ROSINA measured refractories sputtered off the comet by the interaction of solar wind protons with the surface of the comet. Aims. The origin of different solar system materials is still heavily debated. Isotopic ratios can be used to distinguish between different reservoirs and investigate processes occurring during the formation of the solar system. Methods. ROSINA consisted of two mass spectrometers and a pressure sensor. In the ROSINA Double Focusing Mass Spectrometer (DFMS), the neutral gas of cometary origin was ionized and then deflected in an electric and a magnetic field that separated the ions based on their mass-to-charge ratio. The DFMS had a high mass resolution, dynamic range, and sensitivity that allowed detection of rare species and the known major volatiles. We measured the relative abundance of all three stable silicon isotopes with the ROSINA instrument on board the Rosetta spacecraft. Furthermore, we measured 13C/12C in C2H4, C2H5, and CO. The DFMS in situ measurements indicate that the average silicon isotopic composition shows depletion in the heavy isotopes 29Si and 30Si with respect to 28Si and solar abundances, while 13C to 12C is analytically indistinguishable from bulk planetary and meteorite compositions. Although the origin of the deficiency of the heavy silicon isotopes cannot be explained unambiguously, we discuss mechanisms that could have contributed to the measured depletion of the isotopes 29Si and 30Si.
Fichier principal
Vignette du fichier
aa30584-17.pdf (697.62 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

insu-01518753 , version 1 (13-11-2020)

Identifiants

Citer

Martin Rubin, Kathrin Altwegg, Hans Balsiger, Jean-Jacques Berthelier, André Bieler, et al.. Evidence for depletion of heavy silicon isotopes at comet 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics - A&A, 2017, 601, A123 (9 p.). ⟨10.1051/0004-6361/201730584⟩. ⟨insu-01518753⟩
236 Consultations
41 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More