The largest ones consist of thousands of galaxies and are called “galaxy clusters”. The white smooth colour reveals the circulation of the gas that permeates the space within the galaxies of this galaxy cluster. When two galaxy clusters clash, we can witness the propagation of a pair of massive shock waves through the newly formed cluster, similar to the sonic booms from supersonic aircraft. A global team of astronomers made the most comprehensive study of such cosmic shock waves that were produced during the collision of 2 massive galaxy clusters more than a billion years back, forming the galaxy cluster called Abell 3667. These shock waves are still propagating through the freshly formed galaxy cluster at the very high speed of 1500 km/s, corresponding to a Mach number of 2.5.
A worldwide group of astronomers made the most in-depth images of the largest cosmic shock wave noticeable from earth. These enormous shock waves are much larger than our whole galaxy and they form when clusters of galaxies collide in what are the most energetic events after the Big Bang.
The largest ones include thousands of galaxies and are called “galaxy clusters”. Accidents of galaxy clusters are the most effective events that happen in our Universe since its formation and they can produce magnificent “fireworks” that we can observe utilizing modern radio telescopes.
The enormous galaxy cluster Abell 3667. Specific galaxies are too little to be identified in this image. The white smooth colour shows the distribution of the gas that penetrates the space within the galaxies of this galaxy cluster. The red structures trace the 2 huge shock waves that were created throughout the formation of the galaxy cluster. Credit: Francesco de Gasperin, SARAO
When 2 galaxy clusters clash, we can witness the propagation of a pair of enormous shock waves through the freshly formed cluster, comparable to the sonic booms from supersonic aircraft. An international group of astronomers made the most detailed research study of such cosmic shock waves that were generated during the crash of 2 massive galaxy clusters more than a billion years back, forming the galaxy cluster called Abell 3667. “The shock waves act as giant particle accelerators that accelerate electrons to speeds close to the speed of light.
A zoom-in on the largest of the two shock waves, where the complex filamentary structure is evident. Most of the visible galaxies are not part of the cluster, being either in the background or in front of it. The size of the Milky Way if it was at the very same range of the shock wave is likewise shown. Credit: Francesco de Gasperin, SARAO
These shock waves are still propagating through the newly formed galaxy cluster at the extremely high speed of 1500 km/s, corresponding to a Mach variety of 2.5. This suggests that the shock front would cross the entire Earth in the time required to read this sentence. The size of the primary shock wave is remarkable, spanning the entire width of the galaxy cluster for a total size of 6.5 million light years. For comparison, the Milky Way, the galaxy we reside in, is more than 60 times smaller than this shock wave.
These unique observations were performed utilizing the novel MeerKAT radio telescope, situated in South Africa. This telescope includes 64 individual radio meals that are 13.5 m in size which are dispersed over a location of 8 km.
A view of the orientation of the magnetic field lines throughout the cluster shock. Credit: Francesco de Gasperin, SARAO
“The presence of the shocks in Abell 3667 is found using sharp modifications in the homes of the hot gas, traced by its X-ray emission,” added Prof. Finoguenov at the University of Helsinki, who assisted the research by evaluating the X-ray information, gathered by the XMM-Newton observatory.
