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Wallner A, Froehlich MB, Hotchkis MAC, Kinoshita N, Paul M, Martschini M, Pavetich S, Tims SG, Kivel N, Schumann D, Honda M, Matsuzaki H, Yamagata T. 60Fe and 244Pu deposited on Earth constrain the r-process yields of recent nearby supernovae. Science 2021; 372:742-745. [PMID: 33986180 DOI: 10.1126/science.aax3972] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 04/12/2021] [Indexed: 11/02/2022]
Abstract
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.
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Affiliation(s)
- A Wallner
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia. .,Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - M B Froehlich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - M A C Hotchkis
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - N Kinoshita
- Institute of Technology, Shimizu Corporation, Tokyo 135-8530, Japan
| | - M Paul
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - M Martschini
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - S Pavetich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - S G Tims
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - N Kivel
- Laboratory of Radiochemistry, Department for Nuclear Energy and Safety, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - D Schumann
- Laboratory of Radiochemistry, Department for Nuclear Energy and Safety, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - M Honda
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Ibaraki 305-8577, Japan
| | - H Matsuzaki
- Micro Analysis Laboratory, Tandem Accelerator, The University Museum, The University of Tokyo, Tokyo 113-0032, Japan
| | - T Yamagata
- Micro Analysis Laboratory, Tandem Accelerator, The University Museum, The University of Tokyo, Tokyo 113-0032, Japan
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Wallner A, Faestermann T, Feige J, Feldstein C, Knie K, Korschinek G, Kutschera W, Ofan A, Paul M, Quinto F, Rugel G, Steier P. Abundance of live ²⁴⁴Pu in deep-sea reservoirs on Earth points to rarity of actinide nucleosynthesis. Nat Commun 2015; 6:5956. [PMID: 25601158 PMCID: PMC4309418 DOI: 10.1038/ncomms6956] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 11/26/2014] [Indexed: 11/09/2022] Open
Abstract
Half of the heavy elements including all actinides are produced in r-process
nucleosynthesis, whose sites and history remain a mystery. If continuously produced,
the Interstellar Medium is expected to build-up a quasi-steady state of abundances
of short-lived nuclides (with half-lives ≤100 My), including actinides
produced in r-process nucleosynthesis. Their existence in today’s
interstellar medium would serve as a radioactive clock and would establish that
their production was recent. In particular 244Pu, a radioactive
actinide nuclide (half-life=81 My), can place strong constraints on recent
r-process frequency and production yield. Here we report the detection of
live interstellar 244Pu, archived in Earth’s deep-sea
floor during the last 25 My, at abundances lower than expected from continuous
production in the Galaxy by about 2 orders of magnitude. This large discrepancy may
signal a rarity of actinide r-process nucleosynthesis sites, compatible with
neutron-star mergers or with a small subset of actinide-producing supernovae. The build-up of short-lived nuclides in the interstellar medium tells
us about production frequency and yield of heavy elements by nucleosynthesis. Wallner
et al. find a low abundance of live interstellar 244Pu detected from the
deep-sea floor, suggesting a rarity for r-process nucleosynthesis sites.
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Affiliation(s)
- A Wallner
- 1] Department of Nuclear Physics, Australian National University, Canberra, Australian Capital Territory 0200, Australia [2] VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
| | - T Faestermann
- Physik Department, Technische Universität München, D-85747 Garching, Germany
| | - J Feige
- VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
| | - C Feldstein
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel
| | - K Knie
- 1] Physik Department, Technische Universität München, D-85747 Garching, Germany [2] GSI Helmholtz-Zentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany
| | - G Korschinek
- Physik Department, Technische Universität München, D-85747 Garching, Germany
| | - W Kutschera
- VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
| | - A Ofan
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel
| | - M Paul
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel
| | - F Quinto
- VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
| | - G Rugel
- Physik Department, Technische Universität München, D-85747 Garching, Germany
| | - P Steier
- VERA Laboratory, Faculty of Physics, University of Vienna, Währinger Strasse 17, A-1090 Vienna, Austria
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