Features of the Energy Spectrum of Cosmic Rays above 2.5 × 10 18 eV Using the Pierre Auger Observatory

THE PIERRE AUGER COLLABORATION, INCLUYE S MOLLERACH

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Lugar: New York; Año: 2020

0031-9007

We report a measurement of the energy spectrum of cosmic rays above 2.5 × 10 18 eV based on215 030 events. New results are presented: at about 1.3 × 10 19 eV, the spectral index changes from2.51 0.03ðstatÞ 0.05ðsystÞ to 3.05 0.05ðstatÞ 0.10ðsystÞ, evolving to 5.1 0.3ðstatÞ 0.1ðsystÞbeyond 5 × 10 19 eV, while no significant dependence of spectral features on the declination is seen in theaccessible range. These features of the spectrum can be reproduced in models with energy-dependent masscomposition. The energy density in cosmic rays above 5×10 18 eV is 1⁄25.66 0.03ðstatÞ 1.40ðsystÞ ×10 53 erg Mpc −3 .