Astro Seminar: David Radice

Title: R-process Nucleosynthesis in Neutron Star Mergers and Beyond

Abstract: Neutron star mergers have long been proposed as a possible astrophysical site of formation for many of the heavy elements, including gold and uranium. The formation of these r-process elements was confirmed by electromagnetic observations following the neutron star merger GW170817, cementing a picture in which neutron star mergers play a dominant role in the production of these elements. However, cracks have started to form in this picture: the merger rate, inferred from LIGO observations, is lower then expected, and there are issues with current galactic chemical evolution predictions at both low and high metallicity. In this talk, I will summarize our current understanding of r-process production in mergers. I will highlight current theoretical uncertainties and recent efforts to address them. Finally, I will discuss recent work in our group suggesting that accretion induced collapse of white dwarf to neutron stars might be a possible alternative channel.

Speaker: David Radice (Pennsylvania State University)