Universe's largest magnetic fields spanning millions of light years have just been discovered

Astronomers claim that they have uncovered the largest magnetic fields ever found in the universe. According to researchers, cosmic collisions between galaxy clusters, which are believed to be the largest gravitationally bound structures in the universe, have created giant magnetic fields, some of which span millions of light years and are dozens of times larger than the Milky Way.

Galaxy collisions result in compression of hot cluster gas, creating arc-like features called "relics". Since their first discovery in 1970, relics have been discovered in over 70 galaxy clusters so far. Astronomers from Bonn and Tautenburg in Thuringia (Germany) zeroed in on 4 of these relics, as part of a new study, to determine if they generated any visible magnetic fields.

"We discovered the so far largest ordered magnetic fields in the universe, extending over 5-6 million light years", Maja Kierdorf from MPIfR Bonn, the project leader and first author of the study said in a statement.

The study, published in the journal Astronomy & Astrophysics, saw scientists use the stadium-sized Effelsberg radio telescope in Germany, to capture images of the four best known collision relics, one of which CIZA J2242+53, for example, has been fondly named 'Sausage'.

New images of the Sausage and other relics taken by the Effelsberg telescope reveal previously unknown details. The images revealed that the relics are very organised structures and that the particles' motions is creating immense magnetic fields. The shape and strength of the relics indicate that galaxy clusters can slam into each other at speeds of over 2,000 kilometres per second.

"The magnetic fields are of similar strength as in our Milky Way, while the measured degrees of polarization of up to 50% are exceptionally high, indicating that the emission originates in an extremely ordered magnetic field," researchers from the Max Planck Institute of Radio Astronomy explained.

The researchers also determined that the Effelsberg telescope was ideal instrument to use when attempting to spot such magnetic fields in the universe. "Now we can systematically search for ordered magnetic fields in galaxy clusters using polarized radio waves," said the study's co-author Rainer Beck.