BEACON TRANSCRIPT – In the slopes of the Andes on the western border of Argentina, cosmic particles finish intergalactic journeys with a bang when they finally overcome the speed of light as they traverse the liquid medium contained in one of the 1660 shallow, plastic basins of water, 3.6 m in diameter, that dot an area over 3000 km2.
The bang is actually a continuum of light produced as ionized particles (which are generated during the collision of cosmic rays with Earth’s atmosphere) move through a dielectric medium faster than light. In turn, this produces a cone of light with an angle of incidence characteristic of the direction and speed of travel by the particle.
Cosmic Rays Hitting Earth Coming from Outside the Milky Way
Researchers at the Pierre Auger Observatory are utilizing the data collected at these surface detectors to identify the celestial sources for some of the highest energy cosmic rays observed on Earth. From 2004 through 2016, this team of scientists was part of a major collaboration which involved more than 400 scientists from 18 countries.
These all collected and analyzed data from the Pierre Auger Observatory, information gathered from 32,187 particles with energies above 8 × 1018 eV. In doing so, the team was able to access unique information about the origins of cosmic rays, enhanced by the observatory’s large zenith angle and fluorescent telescope arrays.
The results of this collaboration have provided valuable insights into the sources of the highest energy particles impacting Earth’s atmosphere. Scientists note that the anisotropy in the arrival direction of the highest energy particles (>8 × 1018 eV) correlates significantly with the density distribution of nearby galaxies within ~100 megaparsecs. This seems to suggest that they have extragalactic sources.
Professor Bruce Dawson of the University of Adelaide and study co-author said: “Supermassive black holes in other active galaxies are spewing out magnetic fields and particles in big jets, and we think in those jets there may be particle acceleration up to these enormous energies.”
Image Source: Wikimedia