AMS measurements of cosmogenic and supernova-ejected radionuclides in deep-sea sediment cores

¹ University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstrasse 17, 1090 Vienna, Austria
² Department of Nuclear Physics, The Australian National University, Canberra, ACT 0200, Australia
³ Physics Department, TU Munich, James-Franck-Straße, 85748 Garching, Germany
⁴ Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany

^a e-mail: jenny.feige@univie.ac.at

Published online: 19 December 2013

Abstract

Samples of two deep-sea sediment cores from the Indian Ocean are analyzed with accelerator mass spectrometry (AMS) to search for traces of recent supernova activity ~2 Myr ago. Here, long-lived radionuclides, which are synthesized in massive stars and ejected in supernova explosions, namely ²⁶Al, ⁵³Mn and ⁶⁰Fe, are extracted from the sediment samples. The cosmogenic isotope ¹⁰Be, which is mainly produced in the Earth's atmosphere, is analyzed for dating purposes of the marine sediment cores. The first AMS measurement results for ¹⁰Be and ²⁶Al are presented, which represent for the first time a detailed study in the time period of 1.7-3.1 Myr with high time resolution. Our first results do not support a significant extraterrestrial signal of ²⁶Al above terrestrial background. However, there is evidence that, like ¹⁰Be, ²⁶Al might be a valuable isotope for dating of deep-sea sediment cores for the past few million years.