Simulation of Cerenkov contamination for cosmic-ray showers observed with the Auger fluorescence telescopes

L. Perrone1,2, C.K. Guerard1 und M. Risse3 für die Auger-Kollaboration
1Universität Karlsruhe, Institut für Experimentelle Kernphysik, Postfach 3640, 76021 Karlsruhe
2Partially supported by BMBF-Verbundforschung
3Forschungszentrum Karlsruhe, Institut für Kernphysik, Postfach 3640, 76021 Karlsruhe

High-energy cosmic rays ( > 1018 eV) can be detected by the observation of fluorescence light emitted by atmospheric nitrogen molecules. The energy reconstruction of the primary particle requires a reliable estimate of the Cerenkov light contamination in the observed signal. A preliminary study of Cerenkov light profiles as received at the telescopes is presented for some hybrid events measured during the Auger prototype phase from December 2001 to April 2002. For this study, the Cerenkov photon angular distribution to shower axis is extracted from CORSIKA-simulated showers.