Gamma-ray signatures from the radioactive decay of r-process nuclei

The study of the rapid neutron capture or "r process" of nucleosynthesis offers the opportunity to glean insight into where the heavy elements (those above iron) on the periodic table are created in nature. Astrophysical sites, namely, supernovae and compact object mergers, e.g. two neutron stars, have long been touted as possible candidates. Gamma-ray spectra from nuclear decays offers unique potential as one of several multi-messenger components associated with these complex events. We report on gamma-ray studies in the late stages of an r-process event after neutron capture has completed and show that the treatment of nuclear isomers is critical to the resultant gamma-ray spectrum.