Transient Radio Signatures from Neutron Star Encounters with QCD Axion Miniclusters

Abstract

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 $\mathcal{O}\left(100\right),days^{-1}$, 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.

Luca Visinelli

Assistant Professor of Theoretical Physics (RTT)

Theoretical physicist working across particle physics, astrophysics, cosmology, and experimental searches.