Measurement of the cosmic ray spectrum above 4 × 1018 eV using inclined events detected with the Pierre Auger Observatory

The Pierre Auger Collaboration

doi:10.1088/1475-7516/2015/08/049

Measurement of the cosmic ray spectrum above 4 × 10¹⁸ eV using inclined events detected with the Pierre Auger Observatory

The Pierre Auger Collaboration

Physics

Universität Siegen
Instituto Superior Tecnico
Università di Torino and Sezione INFN
Fermilab
Université Paris 11
University of São Paulo
Instituto Balseiro
Ohio State University
Instituto de Tecnologías en Detección y Astropartículas (CNEA CONICET UNSAM)
Universidad Tecnológica Nacional
Universidad Nacional Autonoma de Mexico
Universidad de Santiago de Compostela
Universität Hamburg
Università di Napoli 'Federico II' and Sezione INFN
Radboud University Nijmegen
Lehman College
Universidad Complutense de Madrid
University of Bucharest
Universidad Industrial de Santander
Laboratoire de Physique Nucléaire et de Hautes Energies
UJF-Grenoble 1/CNRS-INSU
Observatorio Pierre Auger and Comisión Nacional de Energía Atómica
New York University
University Politehnica of Bucharest
University of Adelaide
Institut für Experimentelle Kernphysik (IEKP)
Bergische Universität Wuppertal
Max-Planck-Institut für Radioastronomie
Universita del Salento
Karlsruhe Institute of Technology (KIT)
Institute of Physics of the Czech Academy of Sciences
Laboratori Nazionali del Gran Sasso
Universidade Federal do Rio de Janeiro
Institute of Nuclear Physics PAN
Colorado State University

Research output: Contribution to journal › Article › peer-review

29 Scopus citations

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 (E_s) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find E_s=(5.12 ± 0.25 (stat)^+1.0 _-1.2 (sys))×10¹⁹ eV.

Original language	British English
Article number	049
Journal	Journal of Cosmology and Astroparticle Physics
Volume	2015
Issue number	8
DOIs	https://doi.org/10.1088/1475-7516/2015/08/049
State	Published - 1 Aug 2015

Keywords

cosmic ray experiments
ultra high energy cosmic rays

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10.1088/1475-7516/2015/08/049

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Cite this

@article{fcddf40af8844900a582b5498c3b4bf2,

title = "Measurement of the cosmic ray spectrum above 4 × 1018 eV using inclined events detected with the Pierre Auger Observatory",

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.",

keywords = "cosmic ray experiments, ultra high energy cosmic rays",

author = "\{The Pierre Auger Collaboration\} and A. Aab and P. Abreu and M. Aglietta and Ahn, \{E. J.\} and \{Al Samarai\}, I. and Albuquerque, \{I. F.M.\} and I. Allekotte and P. Allison and A. Almela and \{Alvarez Castillo\}, J. and J. Alvarez-Mu{\~n}iz and \{Alves Batista\}, R. and M. Ambrosio and A. Aminaei and L. Anchordoqui and S. Andringa and C. Aramo and Aranda, \{V. M.\} and F. Arqueros and N. Arsene and H. Asorey and P. Assis and J. Aublin and M. Ave and M. Avenier and G. Avila and N. Awal and Badescu, \{A. M.\} and Barber, \{K. B.\} and J. B{\"a}uml and C. Baus and Beatty, \{J. J.\} and Becker, \{K. H.\} and Bellido, \{J. A.\} and C. Berat and Bertaina, \{M. E.\} and X. Bertou and Biermann, \{P. L.\} and P. Billoir and Blaess, \{S. G.\} and A. Blanco and M. Blanco and C. Bleve and H. Bl{\"u}mer and M. Boh{\'a}{\v c}ov{\'a} and D. Boncioli and C. Bonifazi and N. Borodai and J. Brack and \{Van Vliet\}, A.",

note = "Publisher Copyright: {\textcopyright} 2015 IOP Publishing Ltd and Sissa Medialab srl.",

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doi = "10.1088/1475-7516/2015/08/049",

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T1 - Measurement of the cosmic ray spectrum above 4 × 1018 eV using inclined events detected with the Pierre Auger Observatory

AU - The Pierre Auger Collaboration

AU - Aab, A.

AU - Abreu, P.

AU - Aglietta, M.

AU - Ahn, E. J.

AU - Al Samarai, I.

AU - Albuquerque, I. F.M.

AU - Allekotte, I.

AU - Allison, P.

AU - Almela, A.

AU - Alvarez Castillo, J.

AU - Alvarez-Muñiz, J.

AU - Alves Batista, R.

AU - Ambrosio, M.

AU - Aminaei, A.

AU - Anchordoqui, L.

AU - Andringa, S.

AU - Aramo, C.

AU - Aranda, V. M.

AU - Arqueros, F.

AU - Arsene, N.

AU - Asorey, H.

AU - Assis, P.

AU - Aublin, J.

AU - Ave, M.

AU - Avenier, M.

AU - Avila, G.

AU - Awal, N.

AU - Badescu, A. M.

AU - Barber, K. B.

AU - Bäuml, J.

AU - Baus, C.

AU - Beatty, J. J.

AU - Becker, K. H.

AU - Bellido, J. A.

AU - Berat, C.

AU - Bertaina, M. E.

AU - Bertou, X.

AU - Biermann, P. L.

AU - Billoir, P.

AU - Blaess, S. G.

AU - Blanco, A.

AU - Blanco, M.

AU - Bleve, C.

AU - Blümer, H.

AU - Boháčová, M.

AU - Boncioli, D.

AU - Bonifazi, C.

AU - Borodai, N.

AU - Brack, J.

AU - Van Vliet, A.

PY - 2015/8/1

Y1 - 2015/8/1

N2 - 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.

AB - 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.

KW - cosmic ray experiments

KW - ultra high energy cosmic rays

UR - https://www.scopus.com/pages/publications/84941649751

U2 - 10.1088/1475-7516/2015/08/049

DO - 10.1088/1475-7516/2015/08/049

M3 - Article

AN - SCOPUS:84941649751

SN - 1475-7516

VL - 2015

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

IS - 8

M1 - 049

ER -