2013ApJ...774L...6W

We investigate the nucleosynthesis of the radionuclide ⁶⁰Fe in electron-capture supernovae (ECSNe). The nucleosynthetic results are based on a self-consistent, two-dimensional simulation of an ECSN as well as models in which the densities are systematically increased by some factors (low-entropy models). ⁶⁰Fe is found to be appreciably made in neutron-rich ejecta during the nuclear quasi-equilibrium phase with greater amounts being produced in the lower-entropy models. Our results, combining them with the yields of core-collapse supernovae in the literature, suggest that ECSNe account for at least 4%-30% of live ⁶⁰Fe in the Milky Way. ECSNe co-produce neutron-rich isotopes, ⁴⁸Ca, ⁵⁰Ti, ⁵⁴Cr, some light trans-iron elements, and possibly weak r-process elements including some radionuclides such as ⁹³Zr, ⁹⁹Tc, and ¹⁰⁷Pd, whose association with ⁶⁰Fe might have been imprinted in primitive meteorites or in the deep ocean crust on the Earth.