Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network, Konkoly Observatory, 1121 Budapest, Hungary.
Institute of Physics, Eötvös Loránd University, 1117 Budapest, Hungary.
Science. 2021 Feb 26;371(6532):945-948. doi: 10.1126/science.aba1111.
The composition of the early Solar System can be inferred from meteorites. Many elements heavier than iron were formed by the rapid neutron capture process (r-process), but the astrophysical sources where this occurred remain poorly understood. We demonstrate that the near-identical half-lives [Formula: see text] of the radioactive r-process nuclei iodine-129 and curium-247 preserve their ratio, irrespective of the time between production and incorporation into the Solar System. We constrain the last r-process source by comparing the measured meteoritic ratio I/Cm = 438 ± 184 with nucleosynthesis calculations based on neutron star merger and magneto-rotational supernova simulations. Moderately neutron-rich conditions, often found in merger disk ejecta simulations, are most consistent with the meteoritic value. Uncertain nuclear physics data limit our confidence in this conclusion.
太阳系早期的组成可以通过陨石来推断。许多比铁重的元素都是通过快速中子捕获过程（r 过程）形成的，但这一过程发生的天体物理源仍未得到很好的理解。我们证明，放射性 r 过程核素碘-129 和锔-247 的近乎相同的半衰期[公式：见正文]保持它们的比例不变，无论它们在产生和纳入太阳系之间的时间间隔如何。我们通过将测量到的陨石比值 I/Cm = 438 ± 184 与基于中子星合并和磁旋转超新星模拟的核合成计算进行比较，来限制最后一个 r 过程源。在合并盘喷射物模拟中经常发现的中等中子丰富条件与陨石值最一致。不确定的核物理数据限制了我们对这一结论的信心。
