Supernova ejecta in ocean cores used as time constraints for nearby stellar groups

Abstract

Evidence of a supernova (SN) event, discussed in Wallner et al., was discovered in the deep-sea crusts with two signals dating back to 2–3 and 7–9 Myr ago. In this contribution, we place constraints on the birth site of the SN progenitors from the ejecta timeline, the initial mass function (IMF), and the ages of nearby stellar groups. We investigated the Scorpius–Centaurus OB Association, the nearest site of recent massive star formation, and the moving group Tucana-Horologium. Using the known stellar mass of the remaining massive stars within these subgroups and factoring in travel time for the ejecta, we have constrained the ages and masses of the SN progenitors by using the IMF and then compared the results to the canonical ages of each subgroup. Our results identify the Upper Scorpius and Lower Centaurus-Crux subgroups as unlikely birth sites for these SNe. We find that Tucana-Horologium is the likely birth site of the SN 7–9 Myr ago, and Upper Centaurus-Lupus is the likely birth site for the SN 2–3 Myr ago.