Precise initial abundance of Niobium-92 in the Solar System and implications for p -process nucleosynthesis.

Autor:	Haba MK; Institute of Geochemistry and Petrology, ETH Zürich, 8092 Zürich, Switzerland; haba.m.aa@m.titech.ac.jp.; Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8551, Japan., Lai YJ; Institute of Geochemistry and Petrology, ETH Zürich, 8092 Zürich, Switzerland.; Macquarie GeoAnalytical, Department of Earth and Environmental Sciences, Macquarie University, Sydney, NSW 2109, Australia., Wotzlaw JF; Institute of Geochemistry and Petrology, ETH Zürich, 8092 Zürich, Switzerland., Yamaguchi A; Antarctic Meteorite Research Center, National Institute of Polar Research, 190-8518 Tokyo, Japan., Lugaro M; Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), 1121 Budapest, Hungary.; Institute of Physics, ELTE Eötvös Loránd University, 1117 Budapest, Hungary.; Monash Centre for Astrophysics, School of Physics and Astronomy, Monash University, VIC 3800, Australia., Schönbächler M; Institute of Geochemistry and Petrology, ETH Zürich, 8092 Zürich, Switzerland.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2021 Feb 23; Vol. 118 (8).
DOI:	10.1073/pnas.2017750118
Abstrakt:	The niobium-92-zirconium-92 ( 92 Nb- 92 Zr) decay system with a half-life of 37 Ma has great potential to date the evolution of planetary materials in the early Solar System. Moreover, the initial abundance of the p -process isotope 92 Nb in the Solar System is important for quantifying the contribution of p -process nucleosynthesis in astrophysical models. Current estimates of the initial 92 Nb/ 93 Nb ratios have large uncertainties compromising the use of the 92 Nb- 92 Zr cosmochronometer and leaving nucleosynthetic models poorly constrained. Here, the initial 92 Nb abundance is determined to high precision by combining the 92 Nb- 92 Zr systematics of cogenetic rutiles and zircons from mesosiderites with U-Pb dating of the same zircons. The mineral pair indicates that the 92 Nb/ 93 Nb ratio of the Solar System started with (1.66 ± 0.10) × 10 -5 , and their 92 Zr/ 90 Zr ratios can be explained by a three-stage Nb-Zr evolution on the mesosiderite parent body. Because of the improvement by a factor of 6 of the precision of the initial Solar System 92 Nb/ 93 Nb, we can show that the presence of 92 Nb in the early Solar System provides further evidence that both type Ia supernovae and core-collapse supernovae contributed to the light p -process nuclei. Competing Interests: The authors declare no competing interest.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu