Description
Axion-like particles (ALPs) can be copiously produced in binary neutron star (BNS) mergers through nucleon-nucleon bremsstrahlung if the ALP-nucleon couplings are sizable. Furthermore, the ALP-photon coupling may trigger conversions of ultralight ALPs into photons in the magnetic fields of the merger remnant and of the Milky Way. This effect would lead to a potentially observable short gamma-ray signal, in coincidence with the gravitational-wave signal produced during the merging process. This event could be detected through multi-messenger observation of BNS mergers employing the synergy between gravitational-wave detectors and gamma-ray telescopes. In this work, we study the sensitivity of current and proposed MeV gamma-ray experiments to detect such a signal. We find that the proposed instruments can reach a sensitivity comparable with the SN 1987A limit.
