NBIA Seminar: Jennifer Barnes

The observation—in light and gravitational waves—of the first neutron star merger, GW170817, provided an amazingly detailed view of these systems. Among the many successes from this single event was the confirmation of long-held theories that neutron star mergers were astrophysical sites of rapid-neutron capture (r-process) nucleosynthesis, a conclusion reached through analysis of emission from GW170817’s radioactively-powered transient (called a kilonova). However, questions remain regarding the precise role of mergers in burning the heaviest elements, in particular whether additional sites are necessary to explain r-process enrichment in all the environments in which it is observed. To answer this question—and to better understand other phenomena involved in merger-driven mass ejection—it is crucial to make a precise accounting of the amount of r-process material ejected in a given merger. I will discuss key nuclear physics uncertainties affecting our understanding of the r-process and present new calculations that reveal how these uncertainties propagate through to models of kilonovae, and thus challenge efforts to infer outflow properties from kilonova observations