Abundance of live ²⁴⁴Pu in deep-sea reservoirs on Earth points to rarity of actinide nucleosynthesis

Author(s)

A. Wallner, T. Faestermann, J. Feige, C. Feldstein, K. Knie, G. Korschinek, W. Kutschera, A. Ofan, M. Paul, F. Quinto, G. Rugel, P. Steier

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.

Organisation(s)

Isotope Physics

External organisation(s)

Technische Universität München, Hebrew University Jerusalem, GSI Helmholtzzentrum für Schwerionenforschung, Australian National University

Journal

Nature Communications

Volume

6

No. of pages

9

ISSN

2041-1723

DOI

https://doi.org/10.1038/ncomms6956

Publication date

01-2015

Peer reviewed

Yes

Austrian Fields of Science 2012

103014 Nuclear physics

Keywords

ASJC Scopus subject areas

General Physics and Astronomy, General Chemistry, General Biochemistry,Genetics and Molecular Biology

Portal url

https://ucrisportal.univie.ac.at/en/publications/9b70d04c-2fbf-4d26-a5fe-0b2684e78788