'Cosmic whisper' observed in the search for dark matter

August 18, 2025

Evrim Yazgin
Cosmos science journalist


A new technique measuring magnetic fields of some of the largest structures in the universe could be the key to identifying the elusive dark matter particles.

But the story begins with something tiny – a theoretical fundamental particle called an axion.

Axions were first proposed by theoretical physicists in the late 1970s to explain subatomic interactions which don’t follow the rules set out in the standard model of particle physics. They may also hold the key to dark matter.

In recent decades, experiments looking for axion dark matter in particle accelerators have popped up. Other experiments – including the CERN Axion Dark Matter eXperiment (ADMX) and CERN Axion Solar Telescope (CAST) – have turned to space to find axions, rather than producing them on Earth.

A new method described in a paper published in Nature Astronomy, takes this to the extreme.

The physicists behind this research have turned to the largest structures in the cosmos: galaxy clusters. These clusters of galaxies can be a quadrillion (1 with 15 zeroes after it) times heavier than our Sun.



Galaxy Cluster Abell 1689. Credit: NASA/Goddard Space Flight Center/Scientific Visualization Studio/ESA/L. Bradley/JHU.

More:
https://cosmosmagazine.com/space/astrophysics/axion-dark-matter-galaxy-cluster/