Radio Lines from accreting Axion Stars
Dennis Maseizik, Sagnik Mondal, Hyeonseok Seong, G\"unter Sigl

TL;DR
This paper proposes that axion stars reaching critical mass can produce detectable radio signals through accretion and parametric resonance, offering a new method to search for axion dark matter with current and future radio telescopes.
Contribution
It introduces a novel mechanism where axion stars emit monochromatic radio lines, enabling constraints on axion-photon coupling across a wide mass range.
Findings
Radio signals from axion stars can be detected by LOFAR, FAST, ALMA, SKA.
Constraints on axion-photon coupling can reach down to 10^{-13} GeV^{-1}.
Axion star signals provide a new observational window for axion dark matter.
Abstract
Axion-like particles, which we call axions, can compose the missing dark matter and may form substructures such as miniclusters and axion stars. We obtain the mass distributions of axion stars derived from their host miniclusters in our galaxy and find a significant number of axion stars reaching the decay mass, the critical mass set by the axion-photon coupling. Axion stars that have reached the decay mass can accrete surrounding axions either via or directly from their host miniclusters, subsequently converting them into radio photons through parametric resonance. We demonstrate that this accretion provides observable signals by proposing two scenarios: 1) external accretion of background dark matter occurring via miniclusters, and 2) internal accretion of isolated systems occurring directly from the minicluster onto its core. The emitted radio photons are nearly monochromatic with…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
