Measurement of the energy spectrum of cosmic rays above 10{sup 18} eV using the Pierre Auger Observatory Abraham, J [National Technological University, Faculty Mendoza (CONICET/CNEA), Mendoza (Argentina)]; Abreu, P [LIP and Instituto Superior Tecnico, Lisboa (Portugal)]; Aglietta, M [Istituto di Fisica dello Spazio Interplanetario (INAF), Universita di Torino and Sezione INFN, Torino (Italy)]; Ahn, E J [Fermilab, Batavia, IL (United States)]; Allard, D [Laboratoire AstroParticule et Cosmologie (APC), Universite Paris 7, CNRS-IN2P3, Paris (France)]; Allen, J [New York University, New York, NY (United States)]; Alvarez-Muniz, J [Universidad de Santiago de Compostela (Spain)]; Ambrosio, M [Universita di Napoli 'Federico II' and Sezione INFN, Napoli (Italy)]; Anchordoqui, L [University of Wisconsin, Milwaukee, WI (United States)]; Andringa, S [LIP and Instituto Superior Tecnico, Lisboa (Portugal)]; Anticic, T [Rudjer Boskovic Institute, 10000 Zagreb (Croatia)]; Anzalone, A [Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo (INAF), Palermo (Italy)]; Aramo, C [Universita di Napoli 'Federico II' and Sezione INFN, Napoli (Italy)]; Arganda, E [Universidad Complutense de Madrid, Madrid (Spain)]; Arisaka, K [University of California, Los Angeles, CA (United States)]; Arqueros, F [Universidad Complutense de Madrid, Madrid (Spain)]; Asorey, H [Centro Atomico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina)]; Assis, P [LIP and Instituto Superior Tecnico, Lisboa (Portugal)]; Aublin, J [Laboratoire de Physique Nucleaire et de Hautes Energies (LPNHE), Universites Paris 6 et Paris 7, CNRS-IN2P3, Paris (France)]; Ave, M [Karlsruhe Institute of Technology - Campus North - Institut fuer Kernphysik, Karlsruhe (Germany)]; University of Chicago, Enrico Fermi Institute, Chicago, IL (United States)] 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ACCURACY; COSMIC RADIATION; ENERGY RESOLUTION; ENERGY SPECTRA; FLUORESCENCE; MEASURING METHODS; NEUTRINO DETECTION; STATISTICS; DETECTION; EMISSION; IONIZING RADIATIONS; LUMINESCENCE; MATHEMATICS; PHOTON EMISSION; RADIATION DETECTION; RADIATIONS; RESOLUTION; SPECTRA DETECTION; EMISSION; IONIZING RADIATIONS; LUMINESCENCE; MATHEMATICS; PHOTON EMISSION; RADIATION DETECTION; RADIATIONS; RESOLUTION; SPECTRA We report a measurement of the flux of cosmic rays with unprecedented precision and statistics using the Pierre Auger Observatory. Based on fluorescence observations in coincidence with at least one surface detector we derive a spectrum for energies above 10{sup 18} eV. We also update the previously published energy spectrum obtained with the surface detector array. The two spectra are combined addressing the systematic uncertainties and, in particular, the influence of the energy resolution on the spectral shape. The spectrum can be described by a broken power law E{sup -g}amma with index gamma=3.3 below the ankle which is measured at log{sub 10}(E{sub ankle}/eV)=18.6. Above the ankle the spectrum is described by a power law with index 2.6 followed by a flux suppression, above about log{sub 10}(E/eV)=19.5, detected with high statistical significance. Available from http://dx.doi.org/10.1016/j.physletb.2010.02.013 Netherlands 2010-03-08 English Journal Article Journal Name: Physics Letters. Section B; Journal Volume: 685; Journal Issue: 4-5; Other Information: DOI: 10.1016/j.physletb.2010.02.013; PII: S0370-2693(10)00187-5; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved. Medium: X; Size: page(s) 239-246 https://doi.org/10.1016/j.physletb.2010.02.013 [] 4-5 685 Journal ID: ISSN 0370-2693; PYLBAJ; TRN: NL10R9132090092 NLN 2012-12-21 21355806