Penn State University
Highest Energy Physics with Auger
The Pierre Auger Observatory measures cosmic ray air showers at energies beyond 1018 eV, using a hybrid technique combining nitrogen fluorescence telescopes and a giant array of water Cherenkov detectors covering 3000 km2. The Observatory is under construction in Argentina, and is more than half complete. The array is operated as it grows, and the accumulated event statistics are already comparable to the entire data set accumulated by the AGASA experiment, and quickly catching up with the HiRes Fly's Eye experiment. The science, design and status of the Auger Observatory will be described, and first measurements of the energy spectrum and arrival directions of the highest energy cosmic rays will be presented.