Document Type
Article
Publication Date
8-1-2015
Abstract
A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×1018 eV, the "ankle", the flux can be described by a power law E-γ with index γ=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12 ± 0.25 (stat)+1.0-1.2 (sys))×1019 eV.
Publication Source (Journal or Book title)
Journal of Cosmology and Astroparticle Physics
Recommended Citation
Aab, A., Abreu, P., Aglietta, M., Ahn, E., Al Samarai, I., Albuquerque, I., Allekotte, I., Allison, P., Almela, A., Alvarez Castillo, J., Alvarez-Muñiz, J., Alves Batista, R., Ambrosio, M., Aminaei, A., Anchordoqui, L., Andringa, S., Aramo, C., Aranda, V., Arqueros, F., Arsene, N., Asorey, H., Assis, P., Aublin, J., Ave, M., Avenier, M., Avila, G., Awal, N., Badescu, A., Barber, K., Bäuml, J., Baus, C., Beatty, J., & Becker, K. (2015). Measurement of the cosmic ray spectrum above 4 × 1018 eV using inclined events detected with the Pierre Auger Observatory. Journal of Cosmology and Astroparticle Physics, 2015 (8) https://doi.org/10.1088/1475-7516/2015/08/049