The UHECR spectrum measured at the Pierre Auger Observatory and its astrophysical implications

PIERRE AUGER COLLABORATION (J. ABRAHAM, ... , A. MARIAZZI, ET AL)

Merida, Mejico

Conferencia; 30th International Cosmic Ray Conference; 2007

The Southern part of the Pierre Auger Observatory, which is nearing completion, hasbeen in stable operation since January 2004 whilst it has grown in size. The largesample of data collected so far has led to a significant improvement to the energyspectrum of UHE cosmic rays over that previously reported by the Pierre AugerObservatory, both in with regard to statistics and systematic uncertainties. In thiscontribution we summarise two measurements of the energy spectrum, one based on thehigh-statistics surface detector data, and the other on the hybrid data, where theprecision of the fluorescence measurements is enhanced by additional information fromthe surface array. The complementarity of the two approaches is emphasised,and results are compared. Possible astrophysical implications of our measurements,and in particular the presence of spectral features, are discussed.