Cosmic radiation is a collective term for all radiations and particles that penetrate from space into the earth's atmosphere. It comes from different sources. One part comes from the sun, another part from outside our solar system. It is believed that supernovae are one of the sources of galactic cosmic rays. The biggest difficulty is explaining the ultra-high-energy cosmic rays. "No process in our Milky Way can produce it, " says Roger Clay of the University of Adelaide.
Clay is one of the supervisors of astronomy student Melanie Johnston-Hollitt, who studied the galaxy cluster Abell 3667. This cluster of 500 galaxies appears to consist of two clusters that collide with each other. The main indication for this is a bow pair that emits radio radiation.
The theorist Kurt Roettiger of the University of Missouri in Columbia had predicted in 1999 that such radiation arcs would be formed in the collision of galaxy clusters in their outer regions. They are generated by shock waves that occur when the thin gas between the galaxies from both clusters collides at a speed of thousands of kilometers per second.
Johnston-Hollitt has conducted observations using the Australia Telescope Compact Array, a series of six radio telescopes. Each of these telescopes has a mirror diameter of 22 meters. Five of the six telescopes are mounted on rails and can move up to six kilometers from the fixed telescope. display