Element abundance patterns in stars indicate fission of nuclei heavier than uranium

• 成果类型: Article
• 署名作者: Roederer, Ian U.; Vassh, Nicole; Holmbeck, Erika M.; Mumpower, Matthew R.; Surman, Rebecca; Cowan, John J.; Beers, Timothy C.; Ezzeddine, Rana; Frebel, Anna; Hansen, Terese T.; Placco, Vinicius M.; Sakari, Charli M.
• 署名单位: University of Michigan System; University of Michigan; Carnegie Institution for Science; United States Department of Energy (DOE); Los Alamos National Laboratory; United States Department of Energy (DOE); Los Alamos National Laboratory; University of Notre Dame; University of Oklahoma System; University of Oklahoma - Norman; State University System of Florida; University of Florida; Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT); Stockholm University; National Science Foundation (NSF); California State University System; San Francisco State University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-11660
• DOI: 10.1126/science.adf1341
• 发表日期: 2023-12-08
• 关键词: r-process; transuranium elements; nucleosynthesis; mergers; origin; light

摘要

The heaviest chemical elements are naturally produced by the rapid neutron-capture process (r-process) during neutron star mergers or supernovae. The r-process production of elements heavier than uranium (transuranic nuclei) is poorly understood and inaccessible to experiments so must be extrapolated by using nucleosynthesis models. We examined element abundances in a sample of stars that are enhanced in r-process elements. The abundances of elements ruthenium, rhodium, palladium, and silver (atomic numbers Z = 44 to 47; mass numbers A = 99 to 110) correlate with those of heavier elements (63 <= Z <= 78, A > 150). There is no correlation for neighboring elements (34 <= Z <= 42 and 48 <= Z <= 62). We interpret this as evidence that fission fragments of transuranic nuclei contribute to the abundances. Our results indicate that neutron-rich nuclei with mass numbers >260 are produced in r-process events.