<sup>60</sup>Fe and <sup>244</sup>Pu deposited on Earth constrain the r-process yields of recent nearby supernovae

doi:10.1126/science.aax3972

GSTDTAP > 气候变化

DOI	10.1126/science.aax3972
	⁶⁰Fe and ²⁴⁴Pu deposited on Earth constrain the r-process yields of recent nearby supernovae
	A. Wallner; M. B. Froehlich; M. A. C. Hotchkis; N. Kinoshita; M. Paul; M. Martschini; S. Pavetich; S. G. Tims; N. Kivel; D. Schumann; M. Honda; H. Matsuzaki; T. Yamagata
	2021-05-14
发表期刊	Science
出版年	2021
英文摘要	The rapid neutron capture process (r-process) produces many of the heavy chemical elements, but the astrophysical settings where it occurs remain unclear. Leading candidates are neutron star mergers and some types of supernovae. Wallner et al. analyzed the plutonium content of a deep-sea crust sample, identifying a few dozen atoms of the r-process isotope plutonium- 244 that were delivered to Earth within the past few million years. There was a simultaneous signal of iron-60, which is known to be produced in supernovae. Comparing the ratios of these isotopes constrains the relative contributions of supernovae and neutron star mergers to r-process nucleosynthesis. Science , this issue p. [742][1] Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust—iron-60 (60Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (244Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of 60Fe to Earth in the last 10 million years and accompanying lower quantities of 244Pu. The 244Pu/60Fe influx ratios are similar for both events. The 244Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources. [1]: /lookup/doi/10.1126/science.aax3972
领域	气候变化 ; 资源环境
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文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/326823
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	A. Wallner,M. B. Froehlich,M. A. C. Hotchkis,et al. ⁶⁰Fe and ²⁴⁴Pu deposited on Earth constrain the r-process yields of recent nearby supernovae[J]. Science,2021.
APA	A. Wallner.,M. B. Froehlich.,M. A. C. Hotchkis.,N. Kinoshita.,M. Paul.,...&T. Yamagata.(2021).⁶⁰Fe and ²⁴⁴Pu deposited on Earth constrain the r-process yields of recent nearby supernovae.Science.
MLA	A. Wallner,et al."⁶⁰Fe and ²⁴⁴Pu deposited on Earth constrain the r-process yields of recent nearby supernovae".Science (2021).