The magnetic field of a galaxy so far away that its light took more than 11 billion years to reach us and thus dates back just 2.5 billion years after the Big Bang, astronomers using the Atacama Large Millimeter/Submillimeter Telescope have detected Array (ALMA).

Through this research astronomers are getting vital clues about how the magnetic fields of galaxies like ours were created.

Using ALMA, the research team, led by James Gitch, Professor of Astrophysics at the University of Hertfordshire, discovered a fully formed magnetic field in the distant galaxy 9io9, similar in structure to that seen in nearby galaxies.

The field is about 1,000 times weaker than Earth’s magnetic field, but extends over 16,000 light years. The results of the research are published in the journal Nature.

Infrared image of the distant galaxy 9io9, shown as a reddish arc curving around a bright nearby galaxy

To make this detection, the team looked for light emitted by dust grains in this galaxy. Galaxies are full of dust grains, and when a magnetic field is present, the grains tend to align and the light they emit becomes polarized, so the light waves oscillate along a preferred direction rather than randomly.

The discovery of a fully developed magnetic field so early in the history of the Universe shows that magnetic fields that span entire galaxies can form rapidly while new galaxies are still developing.

The team theorizes that intense star formation in the early Universe could have played a role in accelerating the development of magnetic fields. Furthermore, these fields can in turn influence how the next generations of stars form.

Many astronomical bodies in the Universe, planets, stars or galaxies, have magnetic fields. It is not clear how early in the life of the Universe and how quickly magnetic fields formed in galaxies, because so far astronomers have only mapped magnetic fields in nearby galaxies.

“We actually know very little about how these fields form, despite the fact that they are quite fundamental to how galaxies evolve,” points out Enrique López Rodriguez, a researcher at Stanford University in the US who participated in the research.