Title: Neutrino, Nucleosynthesis in Neutron Star Mergers and Multi-messenger Observations

Speaker: Dr. Yonglin Zhu (the SAS Institute)

Time: 14:30pm, October 24, 2023

Location: 5-516, PMO Xianlin Campus

Abstract: The first combined observations of the gravitational wave event GW170817 and electromagnetic counterpart AT2017gfo reveal many signs that neutron star mergers could be the primary production site of the heaviest elements in the universe. The nucleosynthesis processes of the heaviest elements in such explosive astrophysical environments involve many aspects of astrophysics, nuclear physics, and atomic physics. However, the interpretation of such events suffers from many uncertainties, such as the type of ejecta, nuclear data, spectral information of newly made nuclei, etc. In this talk, I will investigate the nucleosynthesis of the heaviest elements in neutron star mergers by exploring how r-process isotope productions link to light curve signals. I will demonstrate that individual nuclei, such as Californium-254, contributes significantly more than others in powering the kilonova light curve, which is independent of nuclear physics inputs and within a specific range of astrophysical conditions. Moreover, to estimate the nuclear uncertainties in r-process nucleosynthesis and its impact on the observations, I will discuss our findings in nucleosynthesis-informed kilonova light curve modeling. I will also discuss how neutrino oscillations could dramatically impact the nucleosynthesis processes in neutron star mergers.