https://doi.org/10.1140/epjc/s10052-015-3471-0
Regular Article - Experimental Physics
Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory
1
Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche, Argentina
2
Centro de Investigaciones en Láseres y Aplicaciones, CITEDEF and CONICET, Villa Martelli, Buenos Aires, Argentina
3
Departamento de Física, FCEyN Universidad de Buenos Aires y CONICET, Buenos Aires, Argentina
4
IFLP, Universidad Nacional de La Plata and CONICET, La Plata, Argentina
5
Instituto de Astronomía y Física del Espacio (CONICET-UBA), Buenos Aires, Argentina
6
Instituto de Física de Rosario (IFIR), CONICET/U.N.R. and Facultad de Ciencias Bioquímicas y Farmacéuticas U.N.R., Rosario, Argentina
7
Instituto de Tecnologías en Detección y Astropartículas (CNEA, CONICET, UNSAM) and National Technological University, Faculty Mendoza (CONICET/CNEA), Mendoza, Argentina
8
Instituto de Tecnologías en Detección y Astropartículas (CNEA, CONICET, UNSAM), Buenos Aires, Argentina
9
Observatorio Pierre Auger, Malargüe, Argentina
10
Observatorio Pierre Auger and Comisión Nacional de Energía Atómica, Malargüe, Argentina
11
Universidad Tecnológica Nacional - Facultad Regional Buenos Aires, Buenos Aires, Argentina
12
University of Adelaide, Adelaide, SA, Australia
13
Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, RJ, Brazil
14
Faculdade Independente do Nordeste, Vitória da Conquista, Brazil
15
Universidade de São Paulo, Escola de Engenharia de Lorena, Lorena, SP, Brazil
16
Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
17
Instituto de Física, Universidade de São Paulo, São Paulo, SP, Brazil
18
Universidade Estadual de Campinas, IFGW, Campinas, SP, Brazil
19
Universidade Estadual de Feira de Santana, Feira de Santana, Brazil
20
Universidade Federal da Bahia, Salvador, BA, Brazil
21
Universidade Federal de Pelotas, Pelotas, RS, Brazil
22
Universidade Federal do ABC, Santo André, SP, Brazil
23
Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
24
Universidade Federal Fluminense, EEIMVR, Volta Redonda, RJ, Brazil
25
Rudjer Bošković Institute, 10000, Zagreb, Croatia
26
Faculty of Mathematics and Physics, Institute of Particle and Nuclear Physics, Charles University, Prague, Czech Republic
27
Institute of Physics of the Academy of Sciences of the Czech Republic, Prague, Czech Republic
28
Palacky University, RCPTM, Olomouc, Czech Republic
29
Institut de Physique Nucléaire d’Orsay (IPNO), Université Paris 11, CNRS-IN2P3, Orsay, France
30
Laboratoire de l’Accélérateur Linéaire (LAL), Université Paris 11, CNRS-IN2P3, Orsay, France
31
Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Universités Paris 6 et Paris 7, CNRS-IN2P3, Paris, France
32
Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Grenoble-Alpes, CNRS/IN2P3, Grenoble, France
33
Station de Radioastronomie de Nançay, Observatoire de Paris, CNRS/INSU, Nançay, France
34
SUBATECH, École des Mines de Nantes, CNRS-IN2P3, Université de Nantes, Nantes, France
35
Bergische Universität Wuppertal, Wuppertal, Germany
36
Karlsruhe Institute of Technology - Campus South - Institut für Experimentelle, Kernphysik (IEKP), Karlsruhe, Germany
37
Karlsruhe Institute of Technology - Campus North - Institut für Kernphysik, Karlsruhe, Germany
38
Karlsruhe Institute of Technology - Campus North - Institut für Prozessdatenverarbeitung und Elektronik, Karlsruhe, Germany
39
Max-Planck-Institut für Radioastronomie, Bonn, Germany
40
RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany
41
Universität Hamburg, Hamburg, Germany
42
Universität Siegen, Siegen, Germany
43
Università di Milano and Sezione INFN, Milan, Italy
44
Università di Napoli “Federico II” and Sezione INFN, Napoli, Italy
45
Università di Roma II “Tor Vergata” and Sezione INFN, Roma, Italy
46
Università di Catania and Sezione INFN, Catania, Italy
47
Università di Torino and Sezione INFN, Torino, Italy
48
Dipartimento di Matematica e Fisica “E. De Giorgi” dell’Università del Salento and Sezione INFN, Lecce, Italy
49
Dipartimento di Scienze Fisiche e Chimiche dell’Università dell’Aquila and INFN, L’Aquila, Italy
50
Gran Sasso Science Institute (INFN), L’Aquila, Italy
51
Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo (INAF), Palermo, Italy
52
INFN, Laboratori Nazionali del Gran Sasso, Assergi, L’Aquila, Italy
53
Osservatorio Astrofisico di Torino (INAF), Università di Torino and Sezione INFN, Torino, Italy
54
Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
55
Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV), Mexico, Mexico
56
Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan, Mexico
57
Universidad Nacional Autonoma de Mexico, Mexico, D.F., Mexico
58
IMAPP, Radboud University Nijmegen, Nijmegen, Netherlands
59
KVI - Center for Advanced Radiation Technology, University of Groningen, Groningen, Netherlands
60
Nikhef, Science Park, Amsterdam, Netherlands
61
ASTRON, Dwingeloo, Netherlands
62
Institute of Nuclear Physics PAN, Krakow, Poland
63
University of Łódź, Łódź, Poland
64
Laboratório de Instrumentação e Física Experimental de Partículas - LIP and Instituto Superior Técnico - IST, Universidade de Lisboa - UL, Lisbon, Portugal
65
’Horia Hulubei’ National Institute for Physics and Nuclear Engineering, Bucharest-Magurele, Romania
66
Institute of Space Sciences, Bucharest-Magurele, Romania
67
Physics Department, University of Bucharest, Bucharest, Romania
68
University Politehnica of Bucharest, Bucharest, Romania
69
Experimental Particle Physics Department, J. Stefan Institute, Ljubljana, Slovenia
70
Laboratory for Astroparticle Physics, University of Nova Gorica, Nova Gorica, Slovenia
71
Universidad Complutense de Madrid, Madrid, Spain
72
Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
73
Universidad de Granada and C.A.F.P.E., Granada, Spain
74
Universidad de Santiago de Compostela, Santiago de Compostela, Spain
75
School of Physics and Astronomy, University of Leeds, Leeds, UK
76
Case Western Reserve University, Cleveland, OH, USA
77
Colorado School of Mines, Golden, CO, USA
78
Colorado State University, Fort Collins, CO, USA
79
Colorado State University, Pueblo, CO, USA
80
Department of Physics and Astronomy, City University of New York, New York, USA
81
Fermilab, Batavia, IL, USA
82
Louisiana State University, Baton Rouge, LA, USA
83
Michigan Technological University, Houghton, MI, USA
84
New York University, New York, NY, USA
85
Northeastern University, Boston, MA, USA
86
Ohio State University, Columbus, OH, USA
87
Pennsylvania State University, University Park, PA, USA
88
Enrico Fermi Institute, University of Chicago, Chicago, IL, USA
89
University of Hawaii, Honolulu, HI, USA
90
University of Nebraska, Lincoln, NE, USA
91
University of New Mexico, Albuquerque, NM, USA
* e-mail: tobias.winchen@rwth-aachen.de
Received:
3
October
2014
Accepted:
20
May
2015
Published online:
20
June
2015
Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with 
eV by analyzing cosmic rays with energies above 
eV arriving within an angular separation of approximately 15
. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.
© The Author(s), 2015
