New method to examine the timing of clear up of solar nebula

2014 Fiscal Year Final Research Report

• Project/Area Number: 23340170
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Geochemistry/Astrochemistry
• Research Institution: The University of Tokyo
• Principal Investigator: NAGAO Keisuke 東京大学, 理学(系)研究科(研究院), 教授 (40131619)
• Co-Investigator(Kenkyū-buntansha): SUMINO Hirochika 東京大学, 大学院理学系研究科, 助教 (90332593)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 原始太陽系星雲 / 太陽風 / ガスリッチ隕石 / I-Xe年代 / 星雲散逸 / 中性子照射

Outline of Final Research Achievements

Our solar system grew in dens protoplanetary solar mebula composed of mainly hydrogen and helium gas with minor amounts of heavier elements and dusts. The nebula had dissipated at some stage of the solar system formation, resulted in clear up of the solar system. We intended to give a constraint on the timing of clear up based on noble gas composition and I-Xe age determination for meteorites showing brecciated structure and/or heavily shocked appearance.
As far as the results obtained for several meteorites with heavily shocked melt veins and brecciated structure, they were affected by heavy shock much later than the solar system formation. These data indicate an importance to select samples reserving information at the initial stage of breccia formation. Even though the data did not give clear constraints on the timing of nebular dissipation, they do not contradict the findings obtained before in our laboratory.

Free Research Field

数物系科学