Analysis of Longitudinal Air Shower Profiles measured by the Pierre Auger Observatory

Abstract

We describe the analysis of longitudinal air shower profiles as measured by the fluorescence detectors of the Pierre Auger Observatory and present the measurement of the depth of maximum of extensive air showers, Xmax, with energies >10^18 eV. The measured energy evolution of the average of Xmax and its fluctuations are compared to air shower simulations for different primary particles.Comment: to appear in the Proceedings of the International Symposium on the Recent Progress of Ultra-high Energy Cosmic Ray Observation, Nagoya 201