A colossal shock wave larger than our galaxy travels through space
Now, using the MeerKAT radio telescope in South Africa, a team of astronomers has carried out the most detailed study of these radio structures, obtaining new information on some of the most massive events in the Universe. "These structures are full of surprises and much more complex than we initially thought," said astronomer Francesco de Gasperin of the University of Hamburg in Germany and the National Institute of Astrophysics in Italy.
"The Shockwaves act as gigantic particle accelerators that accelerate electrons to speeds close to the speed of light. When these fast electrons pass through a magnetic field they emit the radio waves we see ".
The clusters of galaxies are the largest structures in the Universe that are bound together by gravity. They can be absolutely gigantic, containing hundreds or thousands of individual galaxies. Galaxies and galaxy clusters travel along the filaments of the cosmic network to the nodes of the clusters, where they join together to form even larger clusters.
These epic events happen at high speed, generating cluster-scale shock waves that propagate through space, even at high speed. This particular cluster, called Abell 3667, is still merging. At least 550 galaxies have been associated with it, and shock waves are propagating through it at speeds of around 1,500 kilometers per second.
The shocks associated with cluster mergers are known as radio relics and can be used to probe the properties of intergalactic space within the cluster, known as intraluster medium. Abell 3667, about 700 million light-years away, is relatively close to us, and also quite massive, which means it is an excellent target to study.
Since the cluster is located in the southern sky. , astronomers were able to look at it with one of the most sensitive radio telescopes in the world. MeerKAT is a precursor and pathfinder for the Square Kilometer Array (SKA) which is currently being developed in Australia and South Africa to provide an unprecedented radio eye on the sky. The observations from MeerKAT, and those from the Australian Square Kilometer Array Pathfinder, are giving us a taste of the future; not only for the SKA, projected to see the first light in 2027, but for what we can find now.
“Our observations have revealed the complexity of the interaction between thermal and non-thermal components in the most of a merging cluster, ”the researchers wrote in their study. "Both the intricate internal structure of the radio relics and the direct sensing of the magnetic drapery around the merging projectile are powerful examples of the nontrivial magnetic properties of the intraluster medium. Thanks to its sensitivity to polarized radiations, MeerKAT will be renewed in the study of these complex phenomena ".
