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

TL;DR

This paper suggests that binary neutron star mergers are the source of the highest energy cosmic rays, explaining their narrow energy range and predicting coincident neutrino and gravitational wave signals.

Contribution

It introduces a novel model linking BNS mergers to UHECRs, accounting for their energy spectrum and associated multi-messenger signals.

Findings

BNS mergers can produce UHECRs beyond 100 EeV.

The model explains the narrow rigidity range of UHECRs.

Predicted neutrino and gravitational wave coincidences.

Abstract

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.