Cosmic rays are the most energetic particles known in the universe, reaching energies beyond 10^20 eV. The origin of those particles, in particular the most energetic ones, is however still unknown. Thanks to data from the Pierre Auger Observatory, operating in Argentina since 2004, important progresses were made, excluding a galactic origin for particles above 4×10^18 eV and suggesting an indication of correlation with the position of starburst galaxies for the highest energy ones. In this talk, the most fundamental results of astrophysical interest will be discussed, including multi-messenger implications.
Astrophysics with ultra-high energy cosmic rays