Abstract: The rich history of the r-process, which began with geochemists and involves more than a dozen Nobel laureates, is reviewed in this talk.The r-process is the mechanism by which half of all nuclei heavier than iron, and involves intense fluxes and rapid captures of neutrons.However, its astrophysical site has long been debated. The recent LIGO/VIRGO detection of gravitational radiation from GW170817 bears the clear signature of a binary neutron star merger and validated a number of theoretical predictions. These included the observations of a short gamma-ray burst was observed 1.7 s following the merger, and an extended optical/infrared afterglow last- ing weeks. The afterglow is the predicted signal of radioactive decays from decompressing neutron-rich matter catastrophically ejected from the merging stars and provides solid evidence that neutron star mergers are a major, if not primary, source of r-process nuclei. Although this idea was proposed nearly 45 years ago by David Schramm and myself, it was largely ignored in favor of a supernova mechanism. Over the last decade, however, evidence has been accumulating in its favor. GW170817 may have finally settled this question, which has been one of the thorniest problems in nuclear physics and astrophysics. This talk presents my personal perspectives of this paradigm shift.
Bio:
James Lattimer is a Distinguished Professor of Physics & Astronomy at Stony Brook University. He received his BS from the University of Notre Dame and PhD from the University of Texas at Austin. In his 1976 PhD thesis, he proposed that the bulk of r-process elements have their origin in decompressing neutron star matter ejected from mergers involving neutron stars, a prediction apparently validated by observations of the neutron star merger GW170817 and its kilonova. He led development of a liquid-droplet model for nuclei in dense matter and produced the first open-source analytic and tabulated equations of state for hydrodynamical simulations of supernovae and neutron star mergers. His detailed models of neutrino emission from proto-neutron stars correctly predicted the essential features of the neutrino emission fortuitously observed from SN 1987A only a few months later. He established the first clear link between neutron star radii and the nuclear symmetry energy. He helped develop minimal cooling paradigm for neutron star cooling, demonstrate that the Cas A neutron star's rapid cooling is likely due to the onset of neutron superfluidity in its core, and suggest that a warm dust 'blob' in the remnant of SN 1987A is probably hiding the long-sought neutron star born in that supernovae. He is a member of NASA's Neutron Star Interior Composition ExploreR (NICER) detector team. He is a Fellow of the APS and has received Alfred P. Sloan and John Simon Guggenheim Fellowships as well as the Hans A. Bethe Prize, which is the highest APS honor in nuclear astrophysics.
Host: Prof. Sophia Han
Alternative link:
https://meeting.tencent.com/dm/R5i1MlLWGs1H
#腾讯会议：631678010
会议密码：123456