Searching for Axion Dark Matter using Radio Telescopes

TL;DR

This paper explores the potential of next-generation radio telescopes, specifically SKA-mid, to detect axion dark matter through their two-photon coupling, focusing on astrophysical environments like the Galactic centre.

Contribution

It assesses the sensitivity of SKA-mid to axion signals in the 1.7-57 μeV mass range, considering astrophysical magnetic field uncertainties and spectral features.

Findings

SKA-mid can probe axion couplings down to 10^{-16} GeV^{-1}

Observations of the Galactic centre are promising for axion detection

Spectral features can help distinguish axion signals from background

Abstract

We investigate the use of next generation radio telescopes such as the Square Kilometre Array (SKA) to detect axion two-photon coupling in the astrophysical environment. The uncertainty surrounding astrophysical magnetic fields presents new challenges, but with a frequency range corresponding to axions of mass $1.7-57\mu$eV and a spectral profile with a number of distinguishing features, SKA-mid offers a tantalising opportunity to constrain axion dark matter properties. To determine the sensitivity of SKA-mid to an axion signal, we consider observations of the Galactic centre and interstellar medium, and find that this new telescope could allow us to probe axion couplings $\gtrsim10^{-16}$GeV$^{-1}$.