Intergalactic Bridge Spanning 10 Million Light-Years Discovered

Galaxy clusters are large structures in the universe that can contain up to thousands of galaxies bound together by a gravitational field.

For example, our own galaxy, Andromeda, and other galaxies are part of the Local Group, itself a part of the Virgo Cluster that contains about 2000 galaxies.

The Milky Way has two dwarf galaxies, the Large and Small Magellanic Clouds, as two neighbors, and it’s feeding mainly on the smaller one. The two Magellanic Clouds themselves are connected by an intergalactic bridge, a gas stream that stretches over 75,000 light-years.

This shows that galactic bodies don’t evolve in isolation one from the other, and this is true even for enormous clusters of galaxies as a recent research proves.

Intergalactic Bridge Extending for Millions of Light-Years

American Astronomer George Abell initiated the Abell Catalog of Galaxy Clusters in the 1950s.

There are over 4,000 galaxy clusters in the Abell Catalog, and two of these, Abell 0399 and Abell 0401, have been colliding and are now in the process of merging.

An international team of astrophysicists and radio astronomers used the Low-Frequency Array (LOFAR), a network of radio telescopes, to spot intergalactic magnetic fields in the filaments connecting them.

This is hailed as a first-of-its-kind discovery by the researchers, led by F. Govoni from the Italian National Institute of Astrophysics. Govoni said:

“Galaxy clusters … form at the intersections of the cosmic web filaments and grow by accreting substructures in a merging process. Observations made so far with radio telescopes show a ‘halo’ of radio emission in the central areas of some clusters that confirms the existence of a magnetic field and relativistic electrons. Up to now, however, a magnetic field has never been observed in the filaments connecting clusters.”

Per the paper, A radio ridge connecting two galaxy clusters in a filament of the cosmic web, this “ridge of radio-emitting plasma” that extends between the Abell 0399 and 0401 galaxy clusters challenge the current understanding of particle acceleration in the intergalactic space.

Now, astrophysicists have direct evidence that magnetic field filaments do exist in the cosmic web between galaxy clusters. Future observations hope to detect more radio ridges in the intergalactic space around galaxy clusters which could help scientists fine-tune their models and get a better sense of their implications.