Transient Radio Signatures from Neutron Star Encounters with QCD Axion Miniclusters

The QCD axion is expected to form dense structures known as axion miniclusters if the Peccei-Quinn symmetry is broken after inflation. Miniclusters that have survived until today will interact with neutron stars (NSs) in the Milky Way to produce transient radio signals from axion-photon conversion in the NS magnetosphere. We quantify the properties of these encounters and find that they occur frequently [O(1-100)day(-1)], last between a day and a few months, are spatially clustered toward the Galactic Center, and can reach observable fluxes. These radio transients are within reach of current generation telescopes and therefore offer a promising pathway to discovering QCD axion dark matter.

Automated summary

Research shows that frequent encounters between QCD axion miniclusters and neutron stars in the Milky Way result in observable radio signals that last from a day to a few months, clustered towards the Galactic Center. This offers a promising pathway for discovering QCD axion dark matter with current generation telescopes.