Status and recent results of the Pierre Auger Observatory
  The Pierre Auger Observatory aims to determine the nature and origin of the ultra-high energy cosmic rays (UHECR). The Auger hybrid detector combines fluorescence observations of extended air showers, initiated in the atmosphere by these most energetic particles, with measures of the shower front at the ground level by its large array of Cherenkov water tanks. This allows to improve considerably the precision on reconstructed primary cosmic ray parameters, and to make important cross-calibrations between two techniques at these energies, unreachable with accelerator experiments. The Southern Auger site in Argentina is close to completion. The first measure of the primary cosmic rays energy spectrum, the anisotropy search results, and the limit on the photon fraction in the UHECR are discussed. 
Serguei Vorobiov (for the Pierre Auger Collaboration)