Features of the energy spectrum of cosmic rays above 2.5 x 10^18 eV using the Pierre Auger Observatory

THE PIERRE AUGER COLLABORATION (P. HANSEN PERTENECE A LA COLABORACION-ORDEN ALFABETICO)

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Lugar: New York; Año: 2020 p. 1 - 10

0031-9007

We report a measurement of the energy spectrum of cosmic rays above 2.5 × 1018 eV based on215 030 events. New results are presented: at about 1.3 × 1019 eV, the spectral index changes from2.51 0.03ðstatÞ 0.05ðsystÞ to 3.05 0.05ðstatÞ 0.10ðsystÞ, evolving to 5.1 0.3ðstatÞ 0.1ðsystÞ beyond 5 × 1019 eV, while no significant dependence of spectral features on the declination is seen in the accessible range. These features of the spectrum can be reproduced in models with energy-dependent mass composition. The energy density in cosmic rays above 5×1018 eV is ½5.66 0.03ðstatÞ 1.40ðsystÞ × 1053 ergMpc−3.