An article published in the journal “Science” reports the identification of electromagnetic fields along a filament that crosses the approximately 10 million light years between the Abell 0399 and Abell 0401 galaxy clusters. A team of researchers led by Federica Govoni of the National Institute of Astrophysics, Cagliari, used the Low Frequency Array (LOFAR) radio telescope to carry out for the first time measurement of such a structure in radio waves.