Limits on Supernova-Associated ^{60}Fe/^{26}Al Nucleosynthesis Ratios from Accelerator Mass Spectrometry Measurements of Deep-Sea Sediments.

We searched for the presence of ^{26}Al in deep-sea sediments as a signature of supernova influx. Our data show an exponential dependence of ^{26}Al with the sample age that is fully compatible with radioactive decay of terrigenic ^{26}Al. The same set of samples demonstrated a clear supernova ^{60}Fe signal between 1.7 and 3.2 Myr ago. Combining our ^{26}Al data with the recently reported ^{60}Fe data results in a lower limit of 0.18_{-0.08}^{+0.15} for the local interstellar ^{60}Fe/^{26}Al isotope ratio. It compares to most of the ratios deduced from nucleosynthesis models and is within the range of the observed average galactic ^{60}Fe/^{26}Al flux ratio of (0.15±0.05).