| Project/Area Number |
15K13602
|
|---|
| Research Category |
Grant-in-Aid for Challenging Exploratory Research
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Geochemistry/Cosmochemistry
|
|---|
| Research Institution | Tokyo Institute of Technology |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
辻本 拓司 国立天文台, 光赤外研究部, 助教 (10270456)
|
|---|
| Project Period (FY) |
2015-04-01 – 2017-03-31
|
| Project Status |
Completed (Fiscal Year 2016)
|
| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2016: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2015: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
|
|---|
| Keywords | U-Th核年代法 / プレソーラー粒子 / TIMS / r-process / U-Th核年代学 / 銀河化学進化 |
|---|
| Outline of Final Research Achievements |
High precision analysis of U and Th abundances is key for dating presolar grains by U-Th nuclear cosmochronology. In this study, we have developed an isotope dilution TIMS method that enables the determination of 1 pg U and Th with analytical reproducibilities of 0.45% and 1.3%, respectively. The U-Th cosmochronology with this method would provide a 0.7 Gyr of uncertainty for the age of presolar grains determined.
On the other hand, we constrained the origin and evolution of r-process nuclides in the solar vicinity by a new theoretical study that combined the chemical composition of meteorites with galactic chemical evolution models and astronomical observations. Consequently, the timing of last r-process nucleosynthesis that contributed the solar system was determined to be 0.13-0.14 Gyr before the onset of solar system formation.
|
