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

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 similar to 2 Myr ago. Here, long-lived radionuclides, which are synthesized in massive stars and ejected in supernova explosions, namely Al-26, Mn-53 and Fe-60, are extracted from the sediment samples. The cosmogenic isotope Be-10, 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 Be-10 and Al-26 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 Al-26 above terrestrial background. However, there is evidence that, like Be-10, Al-26 might be a valuable isotope for dating of deep-sea sediment cores for the past few million years.