We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to 80 ° and energies in excess of 4 EeV (4 × 10 18 eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. Both analyses are complementary since the angular power spectrum achieves a better performance in identifying large-scale patterns while the needlet wavelet analysis, considering the parameters used in this work, presents a higher efficiency in detecting smaller-scale anisotropies, potentially providing directional information on any observed anisotropies. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. The corresponding p-values obtained after accounting for searches blindly performed at several angular scales, are 1.3 × 10 -5 in the case of the angular power spectrum, and 2.5 × 10 -3 in the case of the needlet analysis. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales. © 2017 IOP Publishing Ltd and Sissa Medialab.
Documento: | Artículo |
Título: | Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory |
Autor: | Multitudinario:402 |
Filiación: | Centro Atómico Bariloche, Instituto Balseiro (CNEA-UNCuyo-CONICET), Argentina Centro de Investigaciones en Láseres y Aplicaciones, CITEDEF, CONICET, Argentina Departamento de Física, Departamento de Ciencias de la Atmósfera y Los Océanos, FCEyN, Universidad de Buenos Aires, Argentina IFLP, Universidad Nacional de la Plata, CONICET, Argentina Instituto de Astronomía y Física Del Espacio (IAFE CONICET-UBA), Argentina Instituto de Física de Rosario (IFIR), CONICET/U.N.R., Facultad de Ciencias Bioquímicas y Farmacéuticas U.N.R., Argentina Instituto de Tecnologías en Detección y Astropartículas (CNEA CONICET UNSAM), Universidad Tecnológica Nacional, Facultad Regional Mendoza (CONICET/CNEA), Argentina Instituto de Tecnologías en Detección y Astropartículas (CNEA CONICET UNSAM), Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica, Argentina Observatorio Pierre Auger, Argentina Observatorio Pierre Auger and Comisión Nacional de Energía Atómica, Argentina Universidad Tecnológica Nacional, Facultad Regional Buenos Aires, Argentina University of Adelaide, Australia Centro Brasileiro de Pesquisas Fisicas (CBPF), Brazil Universidade de São Paulo, Escola de Engenharia de Lorena, Brazil Universidade de São Paulo, Inst. de Física de São Carlos, São Carlos, Brazil Universidade de São Paulo, Inst. de Física, São Paulo, Brazil Universidade Estadual de Campinas (UNICAMP), Brazil Universidade Estadual de Feira de Santana (UEFS), Brazil Universidade Federal de Pelotas, Brazil Universidade Federal Do ABC (UFABC), Brazil Universidade Federal Do Paraná, Setor Palotina, Brazil Universidade Federal Do Rio de Janeiro (UFRJ), Instituto de Física, Brazil Universidade Federal Fluminense, Brazil Universidad Industrial de Santander, Colombia Institute of Physics (FZU), Academy of Sciences of the Czech Republic, Czech Republic Palacky University, RCPTM, Czech Republic University Prague, Institute of Particle and Nuclear Physics, Czech Republic Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud, Univ. Paris/Saclay, CNRS-IN2P3, France Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Universités Paris 6 et Paris 7, CNRS-IN2P3, France Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Grenoble-Alpes, CNRS/IN2P3, France Bergische Universität Wuppertal, Department of Physics, Germany Karlsruhe Institute of Technology, Institut für Experimentelle Kernphysik (IEKP), Germany Karlsruhe Institute of Technology, Institut für Kernphysik (IKP), Germany Karlsruhe Institute of Technology, Institut für Prozessdatenverarbeitung und Elektronik (IPE), Germany RWTH Aachen University, III. Physikalisches Institut A, Germany Universität Hamburg, II. Institut für Theoretische Physik, Germany Universität Siegen, Fachbereich 7 Physik - Experimentelle Teilchenphysik, Germany Gran Sasso Science Institute (INFN), L'Aquila, Italy INAF - Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo, Italy INFN Laboratori Nazionali Del Gran Sasso, Italy INFN, Gruppo Collegato dell'Aquila, Italy INFN, Sezione di Catania, Italy INFN, Sezione di Lecce, Italy INFN, Sezione di Milan, Italy INFN, Sezione di Napoli, Italy INFN, Sezione di Roma Tor Vergata, Italy INFN, Sezione di Torino, Italy Osservatorio Astrofisico di Torino (INAF), Torino, Italy Università Del Salento, Dipartimento di Ingegneria, Italy Università Del Salento, Dipartimento di Matematica e Fisica E. de Giorgi, Italy Università dell'Aquila, Dipartimento di Scienze Fisiche e Chimiche, Italy Università di Catania, Dipartimento di Fisica e Astronomia, Italy Università di Milano, Dipartimento di Fisica, Italy Università di Napoli federico II, Dipartimento di Fisica Ettore Pancini, Italy Università di Roma Tor Vergata, Dipartimento di Fisica, Italy Università Torino, Dipartimento di Fisica, Italy Benemérita Universidad Autónoma de Puebla (BUAP), Mexico Centro de Investigación y de Estudios Avanzados Del IPN (CINVESTAV), Mexico Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas, Instituto Politécnico Nacional (UPIITA-IPN), Mexico Universidad Autónoma de Chiapas, Mexico Universidad Michoacana de San Nicolás de Hidalgo, Mexico Universidad Nacional Autónoma de México, Mexico Institute for Mathematics Astrophysics and Particle Physics (IMAPP), Radboud Universiteit, Nijmegen, Netherlands KVI - Center for Advanced Radiation Technology, University of Groningen, Netherlands Nationaal Instituut voor Kernfysica en Hoge Energie Fysica (NIKHEF), Netherlands Stichting Astronomisch Onderzoek in Nederland (ASTRON), Dwingeloo, Netherlands Institute of Nuclear Physics PAN, Poland University of Lódź, Faculty of Astrophysics, Poland University of Lódź, Faculty of High-Energy Astrophysics, Poland Laboratorio de Instrumentacao e Fisica Experimental de Particulas - LIP, Instituto Superior Técnico - IST, Universidade de Lisboa - UL, Portugal Horia Hulubei National Institute for Physics and Nuclear Engineering, Romania Institute of Space Science, Romania University of Bucharest, Physics Department, Romania University Politehnica of Bucharest, Romania Experimental Particle Physics Department, J. Stefan Institute, Slovenia Laboratory for Astroparticle Physics, University of Nova Gorica, Slovenia Universidad Complutense de Madrid, Spain Universidad de Granada, C.A.F.P.E., Spain Universidad de Santiago de Compostela, Spain Case Western Reserve University, United States Colorado School of Mines, United States Colorado State University, United States Department of Physics and Astronomy, Lehman College, City University of New York, United States Fermi National Accelerator Laboratory, United States Louisiana State University, United States Michigan Technological University, United States New York University, United States Northeastern University, United States Ohio State University, United States Pennsylvania State University, United States University of Chicago, United States University of Hawaii, United States University of Nebraska, United States University of New Mexico, United States School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom Max-Planck-Institut für Radioastronomie, Bonn, Germany SUBATECH, École des Mines de Nantes, CNRS-IN2P3, Université de Nantes, France |
Palabras clave: | Cosmic ray experiments; ultra high energy cosmic rays |
Año: | 2017 |
Volumen: | 2017 |
Número: | 6 |
DOI: | http://dx.doi.org/10.1088/1475-7516/2017/06/026 |
Título revista: | Journal of Cosmology and Astroparticle Physics |
Título revista abreviado: | J. Cosmol. Astroparticle Phys. |
ISSN: | 14757516 |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14757516_v2017_n6_p_Multitudinario |