Hokkaido University Graduate School of Science
Hokkaido University Graduate School of Science
出版者
宇宙航空研究開発機構宇宙科学研究本部
出版者（英）
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA/ISAS)
雑誌名
第38回月・惑星シンポジウム
雑誌名(英)
Proceedings of the 38th ISAS Lunar and Planetary Symposium
ページ
128 - 131
発行年
2006-03
抄録（英）
Compositional evolution of the inner portion of a protoplanetary disk at late accretion stage is examined to reproduce the evolution of the solar nebula inferred from information about chondrites, especially about their O-isotopic compositions and redox states. Temporal variation of disk composition is simulated by performing numerical calculation for advective-diffusion in accretion disk and taking into account the effects of preferential dust migration and evaporation of H2O ice and organics. The estimated time scale of compositional evolution is consistent with chronological suggestion for the interval between formation of CAIs (Ca and Al rich Inclusions) and chondrules. If the disk accretion rate rapidly decays, C/O ratio of innermost disk significantly changes. A reduced environment which can produce SiC would be formed at the inner edge of disk. Heterogeneous recycling of produced SiC would have controlled the redox state of chondrites.
Evolution of oxygen isotopic composition and C/O ratio at late stage of protoplanetary accretion disk
