30TH INTERNATIONAL COSMIC RAY CONFERENCE Effects of the energy error distribution of fluorescence telescopes on the UHECR energy spectrum

Abstract: In order to investigate the effects of the fluorescence energy error distributions on the determi-nation of the ultra high energy cosmic ray (UHECR) spectrum we developed a Monte Carlo simulation of fluorescence telescopes using the HiRes and Auger telescopes as examples. We show that the energy error distribution (EED) for this kind of detector cannot be adequately represented by Gaussian or Log-normal ditributions. We then compare the expected UHECR with one convolved using the determided EEDs. We conclude that the convolved energy spectrum will be smeared but not enough to affect the GZK cutoff detection. We also investigate the effects of possible systematic errors on Fluorescence yield (FY) mesurements on the UHECR spectrum and conclude that a FY error between 10 % and 30 % can match the flux measured by the HiRes and AGASA collaborations