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

Understand

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.