Dissertation Award in Nuclear Physics Talk: Constraining the r-process with Observation and Theory

The astrophysical origins of the heaviest elements found both inside and outside the Solar System are unknown, though neutron star mergers (NSMs) have been observationally confirmed as one such cosmic factory. As we are still early in the era of direct NSM detections and multimessenger follow-up, these invaluable data for which to study the rapid neutron-capture (r-) process are currently sparse. In lieu of direct observables, we can invoke an indirect source of data: metal-poor stars. Long after merger, metal-poor stars can host in their atmospheres signatures of the historical explosive events that produced the heavy elements. Like unique fingerprints, the elemental patterns in stellar spectra unveil distinct conditions under which the elements were synthesized. This talk will discuss how my thesis work uses actinide measurements in metal-poor stars to test the conditions of the r-process occurring in NSM sites. By combining stellar actinide measurements with modeling of the astrophysical events that could have produced them, I place new constraints on the r-process site and nuclear physics far from stability. This work demonstrates a unique and adaptable route by which the elemental signatures of metal-poor stars can help understand the astrophysics and nuclear physics of the r-process.