Latest results of the Pierre Auger Observatory

The Pierre Auger Observatory measures extensive air showers induced by ultra-high energy cosmic rays using two methods: a sampling of the shower particles at the ground level and the detection of the fluorescence light emitted by the air molecules after the shower crossing. The southern site of the Pierre Auger Observatory is acquiring data since 2004. The first results were published few years ago. This article is dedicated to the presentation of the last results, taking into account the data up to end of March 2009. The energy spectrum, the anisotropies in the arrival directions and the mass composition of the cosmic rays are discussed here as well as the extrapolations of the proton–air cross-section in the hadronic models.