Scientists have detected the most energetic cosmic rays ever recorded, with energies of up to 40 teraelectronvolts (TeV), or 40,000 times the energy of the visible spectrum of electrons. The rays, which included electrons and positrons, were observed by the High Energy Space Telescope System (HESS) in Namibia.
Because cosmic rays lose energy as they travel through space, detecting them at such high energies suggests that their origin may lie within a few thousand light-years of Earth.
Cosmic rays are high-energy particles produced by a variety of sources, including the Sun, supernova explosions, rapidly rotating neutron stars (pulsars), and unknown sources. When these rays collide with the Earth's upper atmosphere, they create beams of particles that can be detected on the surface. However, reconstructing the original rays from these beams is a complex and uncertain process.
To detect the cosmic ray electrons, the researchers used HESS, a system of five 12-meter-diameter telescopes located in the Khomas Plateau, Namibia.
For a decade, these telescopes have been scanning the upper atmosphere for traces of Cherenkov radiation, which is created when particles move faster than the speed of light in that medium.
The detection of cosmic rays at such high energies suggests that they may come from a small number of sources close to the Solar System, within a few thousand light-years, a very small distance compared to the size of the Milky Way, which is about 100,000 light-years across.
This discovery opens up opportunities for further research into high-energy cosmic ray sources near Earth, helping to better understand cosmic phenomena and particle acceleration processes in space.
Scientists hope that further studies will determine the exact origin of these cosmic rays, contributing to the construction of more accurate models of the universe and related phenomena.
