报告题目：Neutron Star Merger and Supernova Nucleosynthesis:Impact on Nuclear Physics and Neutrino Physics

　　报告人: Prof. Toshitaka Kajino (Beihang University)

　　报告时间：2017年12月20日（星期三）上午10:00

　　报告地点：近代物理所6号楼学术报告厅

　　Abstract

　　GW170817 was really an event of the century that has opened the window to the frontier of multi-messenger astronomy and astrophysics. Gravitational waves from most likely the merging neutron stars were clearly detected in LIGO-Virgo collaboration, and optical and near-infrared emissions observed in several Telescopes are consistent with those from radiative decays of r-process nuclei which are predicted theoretically in the nucleosynthesis calculation. Neutrinos were not detected unfortunately because of their too low flux from GW170817 that occurred at a distance 0.13 Gly away. Many more events to come in the near future would undoubtedly provide valuable information of the event rate and the distribution of binary neutron star mergers (NSMs) in the local Universe. We now await a nearby GW event (probably once per one thousand years in our Milky Way) for spectroscopic observations to identify if the r-process elements are really synthesized in NSMs.

　　Not only the NSMs but core-collapse supernovae (of both magneto-hydrodynamic jet supernovae; MHD Jet-SNe, and neutrino-driven wind supernovae; ν-SNe) are viable candidates for the r-process sites. NSMs could not contribute to the early Galaxy for cosmologically long merging time-scale for slow GW radiation, while MHD Jet-SNe can contribute from the early epoch of Galaxy formation and explain the “universality” which was observed in abundance pattern of metal poor stars. However, the NSM is still a possible nucleosynthetic site for the solar-system abundance as suggested by the observed afterglow associated with GW170817. We would like to propose a novel solution to this twisted problem by carrying out both NSM and SN r-process nucleosynthesis calculations and numerical simulation of Galactic chemo-dynamical evolution. We will also discuss the impact of nuclear structure physics on the SN nucleosynthesis and the physics of neutrino oscillations (including all three MSW, collective and vacuum oscillations).