The flux of ultra-high energy cosmic rays above 3×1017 eV has been measured with unprecedented precision at the Pierre Auger Observatory. The flux of the cosmic rays is determined by four different measurements. The surface detector array provides three data sets, two formed by dividing the data into two zenith angle ranges, and one obtained from a nested, denser detector array. The fourth measurement is obtained with the fluorescence detector. By combing all four data sets, the all-sky flux of cosmic rays is determined. The spectral features are discussed in detail and systematic uncertainties are addressed.
Performance and simulation of the surface detector array of the TAx4 experiment
