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HK: Fachverband Physik der Hadronen und Kerne

HK 40: Nukleare Astrophysik

HK 40.5: Vortrag

Donnerstag, 20. März 2014, 15:30–15:45, HZ 5

Search for Supernova-produced ⁶⁰Fe in the Earth’s Fossil Record — •Shawn Bishop¹, Peter Ludwig¹, Ramon Egli², Valentyna Chernenko¹, Thomas Faestermann¹, Nicolai Famulok¹, Leticia Fimiani¹, Thomas Frederichs³, Jose Gomez¹, Karin Hain¹, Marianne Hazlik⁴, Gunther Korschinek¹, Silke Merchel⁵, and Georg Rugel⁵ — ¹TU München, Physik Department — ²ZAMG, Wien — ³Universität Bremen, Geowissenschaften — ⁴TU München, Fakultät für Chemie — ⁵HZDR, Dresden

Approximately 1.8 to 2.8 Myr before the present our planet was subjected to the debris of a supernova explosion. The terrestrial proxy for this event was the discovery of live atoms of ⁶⁰Fe in a deep-sea ferromanganese crust [Knie et al., Phys. Rev. Lett. (2004)]. The signature for this supernova event should also reside in magnetite (Fe₃O₄) magnetofossils produced by magnetotactic bacteria extant at the time of the Earth-supernova interaction; these bacteria were and are ubiquitous in all ocean sediments. We have conducted accelerator mass spectrometry (AMS) measurements, searching for live ⁶⁰Fe in the magnetofossil component of a Pacific Ocean sediment core (ODP Core 848); additional AMS measurements are now ongoing with a second sediment core (ODP Core 851) in which we expect to find a higher ⁶⁰Fe signal. This talk will present the current preliminary status of our ⁶⁰Fe search results for both sediment cores.