Reconstruction of Extreme Energy Cosmic Ray Events Observed by JEM-EUSO in the ESAF Framework

THOMAS MERNIK; DMITRY NAUMOV; ANDREA SANTANGELO; KENJI SHINOZAKI; FRANCESCO FENU; JULIO CALVO; SYLVIE DAGORET-CAMPAGNE; GUSTAVO MEDINA-TANCO; HIROKO MIYAMOTOK; ALBERTO DANIEL SUPANITSKY; JACEK SZABELSKI

Conferencia; 31st Intenational Cosmic Ray Conference; 2009

The JEM-EUSO (Extreme Universe Space Observatory onboard the ISS Japanese Experiment Module) aims at measuring the extreme energy component of cosmic rays up to the decade of 10^20 eV. When striking the earth’s atmosphere, protons, nuclei and neutrinos interacting with air initiate extensive air showers (EAS). By observingfrom space the fluorescence and Cherenkov light emitted by the EAS, the species, energy and direction of the primary particle can be effectively determined. Due to the altitude of approximately 430 km the instantaneous aperture of JEM-EUSO will be in the order of 105 km2 sr. This allows us to observe the entire shower development with relatively small light absorption. The ESAF (EUSO Simulation andAnalysis Framework) software package has been designed to simulate space-based observation of EAS, taking into account all necessary steps from EAS generation, propagation of light in atmosphere, detector response and eventually reconstruction. In thispaper we will give an overview on the algorithms used for track analysis, geometrical reconstruction and energy measurement. We will illustrate step by step the reconstruction chain and describe how it has been updated to meet JEM-EUSO specification.