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Transient Radio Signatures from Neutron Star Encounters with QCD Axion Miniclusters.
Thomas D P Edwards1,2, Bradley J Kavanagh2,3, Luca Visinelli2,4
1The Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Center, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden.
Physical Review Letters
|October 8, 2021
Summary
Dense axion miniclusters may produce detectable radio signals through interactions with neutron stars. These frequent, transient signals, clustered near the Galactic Center, offer a new method for discovering QCD axion dark matter.
Area of Science:
- Particle Physics
- Astrophysics
- Cosmology
Background:
- The QCD axion is a hypothetical particle proposed to solve the strong CP problem.
- If the Peccei-Quinn symmetry breaks after inflation, axions can form dense structures called miniclusters.
- These miniclusters may interact with astrophysical objects, potentially producing observable signals.
Purpose of the Study:
- To investigate the properties of interactions between axion miniclusters and neutron stars.
- To determine the characteristics of the resulting transient radio signals.
- To assess the feasibility of detecting these signals with current astronomical instruments.
Main Methods:
- Simulating the encounters between axion miniclusters and Milky Way neutron stars.
- Modeling the axion-photon conversion process within neutron star magnetospheres.
- Quantifying the expected frequency, duration, spatial distribution, and flux of the radio transients.
Main Results:
- Encounters between miniclusters and neutron stars are predicted to occur frequently, on the order of 1-100 per day.
- The resulting radio transients are expected to last from a day to a few months.
- These signals are spatially clustered towards the Galactic Center and can reach observable fluxes.
Conclusions:
- The predicted radio transients are within the detection capabilities of current telescopes.
- This provides a promising new avenue for the discovery of QCD axion dark matter.
- Observing these signals could confirm the existence of axion miniclusters and shed light on dark matter composition.
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