The Structure of the Solar Nebula from Cometary Composition
Résumé
The comparison of the D/H ratio in water measured in Oort cloud comets with meteoritic values assumed to be representative of the value in ices falling from the presolar cloud implies that that the deuterated water was reprocessed in vapor phase in the early solar nebula up to the region of formation of comets. This constrains the evolution of the radial distribution of temperature in the equatorial plan produced from turbulent models of the solar nebula. Such a model has been elaborated by Hersant et al. (2001 ApJ 554 391). It permitted Bockelee-Morvan et al. (2002 A&A 354 1107) to investigate the transport of crystalline silicates from the inner to outer disks regions and to reproduce the mass fraction of these silicates measured in comet Hale-Bopp. The same model was used to evaluate the trapping of volatiles in the form of clathrate hydrates in the cooling nebula. This led Iro et al. (2003 Icarus 161 513) to propose a quantitative interpretation of the strong deficiency of N2 with respect to CO observed in three Oort cloud comets.