Recent near-Earth supernovae probed by global deposition of interstellar radioactive 60 Fe

Author(s)

A. Wallner, J. Feige, N. Kinoshita, Michael Paul, L. K. Fifield, R. Golser, M. Honda, U. Linnemann, H. Matsuzaki, S. Merchel, G. Rugel, S. G. Tims, P. Steier, T. Yamagata, Stephan Winkler

Abstract

The rate of supernovae in our local Galactic neighbourhood within a distance of about 100 parsecs from Earth is estimated to be one every 2-4 million years, based on the total rate in the Milky Way (2.0 ± 0.7 per century

^1,2). Recent massive-star and supernova activity in Earth's vicinity may be traced by radionuclides with half-lives of up to 100 million years

^3-6, if trapped in interstellar dust grains that penetrate the Solar System. One such radionuclide is

⁶⁰Fe (with a half-life of 2.6 million years)

^7,8, which is ejected in supernova explosions and winds from massive stars

^1,2,9. Here we report that the

⁶⁰Fe signal observed previously in deep-sea crusts

^10,11 is global, extended in time and of interstellar origin from multiple events. We analysed deep-sea archives from all major oceans for

⁶⁰Fe deposition via the accretion of interstellar dust particles. Our results reveal 60 Fe interstellar influxes onto Earth at 1.5-3.2 million years ago and at 6.5-8.7 million years ago. The signal measured implies that a few per cent of fresh

⁶⁰Fe was captured in dust and deposited on Earth. Our findings indicate multiple supernova and massive-star events during the last ten million years at distances of up to 100 parsecs.

Organisation(s)

Isotope Physics

External organisation(s)

Australian National University, Technische Universität Berlin, Shimizu Corporation, Hebrew University Jerusalem, University of Tsukuba, Senckenberg Naturhistorische Sammlungen Dresden, University of Tokyo, Helmholtz-Zentrum Dresden-Rossendorf, Nihon University

Journal

Nature

Volume

532

Pages

69-72

No. of pages

4

ISSN

0028-0836

DOI

https://doi.org/10.1038/nature17196

Publication date

04-2016

Peer reviewed

Yes

Austrian Fields of Science 2012

103014 Nuclear physics, 103004 Astrophysics

Keywords

Portal url

https://ucrisportal.univie.ac.at/en/publications/a37ff04b-ddc8-42fe-931a-acd116525825