From a galaxy far far away
Ultra-High Energy Cosmic Rays come from Galaxies far away, not from the Milky Way. The result, published this week on Science, comes from the Pierre Auger Observatory, located in the Mendoza province of Argentina. It answers questions scientist ask themselves since half a century: from where Ultra-High Cosmic Rays come from? Are they produced in our Galaxy or do they come from faraway galaxies? "This discovery clearly indicates the extra-galactic origin of these particles" says Daniele Martello, Professor at the l’Università del Salento and Auger-Italy coordinator "It is a first important step to be followed by many others to the goal of identifying the sources of these particles".
The Pierre Auger Observatory is the world biggest Cosmic Rays Observatory ever built. It is run by an international collaboration featuring more than 400 scienziati from 18 countries. The Milano Auger group is composed by Lorenzo Caccianiga, Marco Giammarchi, Giovanni Consolati and the coordinator Lino Miramonti.