Potential of the MeerKAT telescope to detect the stimulated decay of axion-like particles

TL;DR

This paper explores the potential of the MeerKAT radio telescope to detect radio signals from stimulated decay of axion-like particles, which could provide evidence for cold dark matter candidates.

Contribution

It demonstrates that MeerKAT can probe ALP parameter space at levels comparable to current and future experiments like CAST and IAXO.

Findings

MeerKAT can reach current CAST experiment limits.

Potential to match IAXO experiment sensitivity.

Radio signatures from ALP decay are detectable with MeerKAT.

Abstract

A prominent aspect of the hunt for cold dark matter is looking for light scalar candidates such as axion-like particles (ALPs). The coupling between ALPs and photons allows for the spontaneous decay of ALPs into pairs of photons. It has been previously shown that stimulated ALP decay rates can become significant on cosmic time scales. Furthermore, it has been claimed, in several recent works, that ALPs can gravitationally thermalize and form macroscopic condensates. Consequently, the photon occupation number of ambient populations (like the cosmic microwave background) can receive Bose enhancement in dense ALP clumps and grows exponentially. For cold dark matter ALPs, this can lead to radio emissions produced from this process and could be observed by the forthcoming radio telescopes. In this work, we investigate the detectability of such a radio signature from some astrophysical targets using the MeerKAT radio telescopes. The results show that the MeerKAT telescope is able to probe the ALPs parameter space with limits reaching the current level of the CAST experiment and the potential level of the IAXO experiment with an arcminute visibility taper.