Binary neutron star mergers as the source of the highest energy cosmic rays

We propose that ultrahigh energy cosmic rays are produced in binary neutron star mergers. This scenario can account for the heretofore inexplicable narrow rigidity range of UHECRs, because the jets of BNS mergers are generated by a gravitationally-driven dynamo and thus are nearly identical due to the narrow range of BNS masses. Observed UHECRs with energies well beyond 100 EeV can be explained as $r$-process nuclei, without invoking an exotic source class. Evidence for this mechanism, and its prediction of coincidences between neutrinos above 10 PeV and gravitational waves, are discussed.