Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf
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60Fe and 244Pu deposited on Earth constrain the r-process yields of recent nearby supernovae
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: 60Fe (half-life 2.6 million years, Myr), predominantly produced in massive stars and ejected in SN explosions; and 244Pu, (half-life 80.6 Myr) produced solely in r-process events. We detect two distinct influxes of 60Fe to Earth in the last 10 Myr 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, implying some contribution from other sources.
Keywords: r process; Supernova; interstellar medium; accelerator mass spectrometry; deep-sea archive; 60Fe; 244Pu
Science 372(2021)6543, 742-745
- Secondary publication expected