The Origin of ²⁰⁵Pb Isotope in the Solar System

Short-lived radionuclides can provide high-precision chronological information, which is very important in the study of the formation and evolution of the solar system. ²⁰⁵Pb is a short-lived nuclide with a half-life of 17.0(9) My and is classified as a pure s-process nucleus. The ²⁰⁵Pb-²⁰⁵Tl decay system can be used as a clock to study the origin of ²⁰⁵Pb in the solar system. In this paper, the isotope yield ratios of ²⁰⁵Pb and ²⁰⁴Pb for AGB stars with different masses and metallicities were calculated using the latest evaluation data of nuclear reaction cross sections in ENDF/B-VIII.0 database. The isotopic abundance ratios of ²⁰⁵Pb and ²⁰⁴Pb in the early solar system were further calculated by the Galactic chemical evolution model. The theoretical result is compared with the experimental measurement result from meteorites produced in the early solar system. It is concluded that the ²⁰⁵Pb nuclide in the solar system may be created during the evolution of AGB stars with masses of 1.5~2.0 M_☉ and metallicities in the range Z = 0.004~0.008.