Document Type
Article
Publication Date
9-16-2020
Department
Department of Physics
Abstract
We report a measurement of the energy spectrum of cosmic rays above 2.5×1018 eV based on 215 030 events. New results are presented: at about 1.3×1019 eV, the spectral index changes from 2.51±0.03(stat)±0.05(syst) to 3.05±0.05(stat)±0.10(syst), evolving to 5.1±0.3(stat)±0.1(syst) 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 [5.66±0.03(stat)±1.40(syst)]×1053 erg Mpc−3.
Publication Title
PHYSICAL REVIEW LETTERS
Recommended Citation
Aab, A.,
Abreu, P.,
Aglietta, M.,
Albury, J. M.,
Allekotte, I.,
Almela, A.,
Fick, B.,
Nitz, D. F.,
Puyleart, A.,
&
et. al.
(2020).
Features of the Energy Spectrum of Cosmic Rays above 2.5 × 10 18 eV Using the Pierre Auger Observatory.
PHYSICAL REVIEW LETTERS,
125(12).
http://doi.org/10.1103/PhysRevLett.125.121106
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/15222
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Publisher’s version of record: https://doi.org/10.1103/PhysRevLett.125.121106