Astronomers have uncovered an unlimited cloud of energetic particles — a ‘mini halo’ — surrounding one of the distant galaxy clusters ever observed, marking a significant step forward in understanding the hidden forces that shape the cosmos.
The mini-halo is at a distance so great that it takes light 10 billion years to achieve Earth, making it probably the most distant ever found, doubling the previous distance known to science.
The invention demonstrates that entire galaxy clusters, amongst the most important structures within the universe, have been immersed in high-energy particles for many of their existence.
Such a mini-halo consists of highly energetic, charged particles within the vacuum between galaxies in a cluster, which together emanate radio waves which might be detected from Earth.
Accepted for publication in The Astrophysical Journal Letters, with the pre-print version of the paper published today. the findings show that even within the early universe, galaxy clusters were already shaped by energetic processes.
The international team of researchers behind the invention was co-led by Julie Hlavacek-Larrondo of Université de Montréal and Roland Timmerman of the Institute for Computational Cosmology of Durham University, within the U.K.
The researchers analysed data from the Low Frequency Array (LOFAR) radio telescope, an unlimited network of over 100,000 small antennae spanning eight European countries. While studying a galaxy cluster named SpARCS1049, the researchers detected a faint, widespread radio signal.They found that it didn’t emanate from individual galaxies, but from an unlimited region of space crammed with high-energy particles and magnetic fields.
Stretching over one million light-years, this diffuse glow is a telltale sign of a mini-halo,a structure astronomers have only been in a position to observe within the nearby universe up until now. “It’s as if we have discovered an unlimited cosmic ocean, where entire galaxy clusters are continuously immersed in high-energy particles,” said Hlavacek-Larrondo.
Added Timmerman: “It’s astonishing to seek out such a robust radio signal at this distance. It means these energetic particles and the processes creating them have been shaping galaxy clusters for nearly the complete history of the universe.”
Two likely explanations
There are two likely explanations behind the formation of the mini-halo.
One is that there are supermassive black holes on the hearts of galaxies inside a cluster that may eject streams of high-energy particles into space. Nevertheless, astronomers are still trying to grasp how these particles would give you the chance to migrate away from the black hole to create such a big cloud of particles, while maintaining a lot of their energy.
The second explanation is cosmic particle collisions. That is when charged particles inside the hot plasma of the galaxy cluster collide at near-light speeds, smashing apart into the highly energetic particles that might be observed from Earth.
This latest discovery provides a rare have a look at what galaxy clusters were like just after they formed, the astronomers say.
It not only shows that galaxy clusters have been infused with these high-energy particles for billions of years greater than previously known, however it also allows astronomers to check where these high-energy particles come from.
It suggests that black holes and/or high-energy particle collisions have been enriching the environment of galaxy clusters much sooner than expected, keeping them energized over billions of years.
With newer telescopes being developed similar to the Square Kilometer Array (SKA), scientists will give you the chance to detect even fainter signals and further explore the role of magnetic fields, cosmic rays, and energetic processes in shaping the Universe, the astronomers say.
“We are only scratching the surface of how energetic the early Universe really was,” said Hlavacek-Larrondo. “This discovery gives us a brand new window into how galaxy clusters grow and evolve, driven by each black holes and high-energy particle physics.”