Transient Radio Signatures from Neutron Star Encounters with QCD Axion Miniclusters.

Thomas D. P. Edwards,Luca Visinelli,Bradley J. Kavanagh,Christoph Weniger

doi:10.1103/physrevlett.127.131103

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 MilkyWay 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.

Highlights

The QCD axion is expected to form dense structures known as axion miniclusters if the Peccei-Quinn symmetry is broken after inflation
In this Letter, we propose and characterize a new class of radio source, arising from encounters between neutron stars (NSs) and overdense structures known as axion miniclusters (AMCs) [28,29,30,31,32,33]. (We use the terms miniclusters and AMCs interchangeably.)
In our companion paper [60], we show that tidal interactions with stars can have a dramatic effect on the survival of AMCs in the Milky Way (MW)

Summary

Introduction

The QCD axion is expected to form dense structures known as axion miniclusters if the Peccei-Quinn symmetry is broken after inflation. Transient Radio Signatures from Neutron Star Encounters with QCD Axion Miniclusters 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.

Results

Conclusion