The Pierre Auger Observatory is conceived to study ultra-high energy cosmic rays from about 10^17 eV to beyond 10^20 eV. It is a multi-hybrid Observatory comprising 1660 surface detector stations spread over an area of 3000 km2 over-looked by 27 imaging Fluorescence telescopes erected at four sites at its periphery. Each of the detector stations consists of a 10 m2 water Cherenkov detector...
We discuss propagation of heavy nuclei at energies higher than 10 19 eV from their sources to the Earth, assuming them to be of extragalactic origin. In extragalactic space nuclei interact with background emission and inevitably decay. Analyzing the content of heavy nuclei arriving the Earth we reveal their energy at the Earth as a function of the source-Earth distance. It is found that the...
