Average shape of longitudinal shower profiles measured at the Pierre Auger Observatory
LIP, Av. Prof. Gama Pinto, 2, Lisboa, Portugal
2 Observatorio Pierre Auger, Av. San Martín Norte 304, 5613 Malargüe, Argentina
Published online: 17 May 2019
The average profiles of cosmic ray shower development as a function of atmospheric depth are measured for the first time with the Fluorescence Detectors at the Pierre Auger Observatory. The profile shapes are well reproduced by the Gaisser-Hillas parametrization at the 1% level in a 500 g/cm2 interval around the shower maximum, for cosmic rays with log(E/eV) > 17.8. The results are quantified with two shape parameters, measured as a function of energy.
The average profiles carry information on the primary cosmic ray and its high energy hadronic interactions. The shape parameters predicted by the commonly used models are compatible with the measured ones within experimental uncertainties. Those uncertainties are dominated by systematics which, at present, prevent a detailed composition analysis.
© The Authors, published by EDP Sciences, 2019
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