Supernova explosions eject copious amounts of material into the interstellar medium. It is possible that supernova ejecta are incorporated into solar system reservoirs. The method of choice for the search for such a signature is accelerator mass spectrometry (AMS), since it allows for the detection of minute concentrations of long-lived radioisotopes such as 53Mn and 60Fe. For searches on Earth, especially 60Fe is especially well suited, since it has only very low terrestrial background. Results from two studies will be presented: The first part will focus on a search for 60Fe in Pacific Ocean marine sediment. A newly developed chemical extraction method was used to target specifically magnetofossils, chains of magnetite crystals produced by magnetotactic bacteria, preventing signal dilution. The advantage of using slow-growing sediments is the preservation of the temporal signature of possible supernova deposition. In the second part, results from a study of 53Mn and 60Fe in lunar samples will be presented. For this purpose, samples from the missions Apollo 12, 15, and 16 were analyzed, in combination with a set of meteoritic samples to estimate background due to galactic cosmic rays. Although the lunar surface does not provide a time-resolved signal due to the lack of sedimentation, one of the big advantages is the possibility to determine the local interstellar fluence of 60Fe at the time of deposition. All measurements were preformed at the AMS facility GAMS at the Maier-Leibnitz-Laboratory in Garching.
