The Cosmic Ray Energy Spectrum and Related Measurements with the Pierre Auger Observatory.

PIERRE AUGER COLL. J. ABRAHAM, M.T.DOVA ET AL

Polonia

Conferencia; 31st International Cosmic Ray Conference; 2009

University of Łódź, Department of High Energy Astrophysics and Department of Astrophysics jointly with The Andrzej Sołtan Institute for Nuclear Studies, Division of Cosmic Ray Physics in Łódź

The flux of cosmic rays above 1018 eV has been measured with unprecedented precision using the Pierre Auger Observatory. Two analysis techniques have been used to extend the spectrum downwards from 3 × 1018 eV, with the lower energies being explored using a novel technique that exploits the hybrid strengths of the instrument. The systematic uncertainties, and in particular the influence of the energy resolution on the spectral shape, are addressed. The spectrum can be described by a broken power-law of index 3.3 below the ankle which is measured at lg(Eankle/eV) = 18.6. Above the ankle the spectrum is described by a power-law / E−2.6 and a flux suppression with lg(E1/2/eV) = 19.6.