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Résumé |
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
are created, 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 1.7s following the merger, and an extended
optical/infrared afterglow lasting 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. |
