Heidelberg 2015 – wissenschaftliches Programm
MS 13.3: Vortrag
Donnerstag, 26. März 2015, 17:45–18:00, PH/HS2
Search for supernova-60Fe in Earth’s microfossil record — •Peter Ludwig1, Shawn Bishop1, Ramon Egli2, Valentyna Chernenko1, Boyana Deneva1, Thomas Faestermann1, Nicolai Famulok1, Leticia Fimiani1, Jose Manuel Gomez Guzman1, Karin Hain1, Gunther Korschinek1, Thomas Frederichs3, Marianne Hanzlik4, Georg Rugel5, and Silke Merchel5 — 1Physik Department, TU München — 2ZAMG, Wien — 3Fachbereich Geowissenschaften, Univ. Bremen — 4Fakultät für Chemie, TU München — 5HZDR Dresden
Supernova (SN) explosions eject copious amounts of material into the interstellar medium. It is possible that supernova ejecta are incorporated into solar system reservoirs. 60Fe is an ideal isotope to search for such a signature, since it is produced in massive stars and can be ejected in their subsequent SN explosions, and has almost no terrestrial background. For this study, the ratio of 60Fe/Fe was determined with AMS using the GAMS setup in Garching, Germany, in a set of samples extracted from two Pacific Ocean sediment cores of 0 to 7 Ma of age. The Fe samples were obtained using a novel chemical extraction technique targeting specifically magnetofossils, chains of magnetite crystals produced by magnetotactic bacteria, and other small-grained Fe-bearing minerals, to prevent signal dilution. Our findings reveal a 60Fe signature in the age range of 1.8-2.5 Ma, which is attributed to input of SN ejecta.