Experimental HEP Seminar

Measuring Ultra-high Energy Cosmic Rays

Javier Gonzalez

Universidad de Granada

The nature and origin of ultra-high energy cosmic rays are two of the outstanding problems in cosmic ray physics. The Pierre Auger observatory is an international collaboration established to study ultra-high-energy cosmic rays. Its southern site, completed within the last year, consists of 1660 water Cherenkov detectors and four fluorescence telescopes. We will comment on the status of the observatory and review some of the latest results. These include the energy spectrum above 10¹⁸ eV and studies on the composition of the primary cosmic ray flux.