RT Journal Article
T1 Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory
A1 Arganda, E.
A1 Arqueros Martínez, Fernando
A1 Blanco Ramos, Francisco
A1 García Pinto, Diego
A1 Ortiz Ramis, Montserrat
A1 Rosado Vélez, Jaime
A1 Vázquez Peñas, José Ramón
AB The Pierre Auger Collaboration has reported. evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > E-th = 5.5 x 10(19) eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > E-th are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above E-th/Z (for illustrative values of Z = 6, 13, 26). If the anisotropies above E-th are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.
PB Iop Publishing
SN 1475-7516
YR 2011
FD 2011-06
LK https://hdl.handle.net/20.500.14352/45091
UL https://hdl.handle.net/20.500.14352/45091
LA eng
NO © 2011 IOP Publishing Ltd and SISSA.Artículo firmado por más de 10 autores (The Pierre Auger Collaboration).We are very grateful to the following agencies and organizations for financial support: Comision Nacional de Energia Atomica, Fundacion Antorchas, Gobierno De La Provincia de Mendoza, Municipalidad de Malargue, NDM Holdings and Valle Las Lenas, in gratitude for their continuing cooperation over land access, Argentina; the Australian Research Council; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Financiadora de Estudos e Projetos (FINEP), Fundacao de Amparo a Pesquisa do Estado de Rio de Janeiro (FAPERJ), Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Ministerio de Ciencia e Tecnologia (MCT), Brazil; AVCR, AV0Z10100502 and AV0Z10100522, GAAV KJB300100801 and KJB100100904, MSMT-CR LA08016, LC527, 1M06002, and MSM0021620859, Czech Republic; Centre de Cal-cul IN2P3/CNRS, Centre National de la Recherche Scientifique (CNRS), Conseil Regional Ile-de-France, Departement Physique Nucleaire et Corpusculaire (PNC-IN2P3/CNRS), Departement Sciences de l'Univers (SDU-INSU/CNRS), France; Bundesministerium fur Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Finanzministerium Baden-Wurttemberg, Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF), Ministerium fur Wissenschaft rind Forschung, Nordrhein-Westfalen, Ministerium fur Wissenschaft, Forschung und Kunst, Baden-Wurttemberg, Germany; Istituto Nazionale di Fisica Nuclear (INFN), Istituto Nazionale di Astrofisica (INAF), Minister dell'Istruzione, dell'Universita e della Ricerca (MIUR), Gran Sasso Center for Astroparticle Physics (CFA), Italy; Consejo Nacional de Ciencia y Tecnologia (CONACYT), Mexico; Ministerie an Onderwijs, Cultuur en Wetenschap, Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), Stichting voor Fundamenteel Onderzoek der Materie (FOM), Netherlands; Ministry of Science and Higher Education, Grant Nos. 1 P03 D 014 30 and N N202 207238, Poland; Fundacao para a Ciencia e a Tecnologia, Portugal; Ministry for Higher Education, Science, and Technology, Slovenian Research Agency, Slovenia; Comunidad de Madrid, Consejeria de Educacion de la Comunidad de Castilla La Mancha, FEDER funds, Ministerio de Ciencia e Innovacion and Consolider-Ingenio 2010 (CPAN), Generalitat Valenciana, Junta de Andalucia, Xunta de Galicia, Spain; Science and Technology Facilities Council, United Kingdom; Department of Energy, Contract Nos. DE-AC02-07CH11359, DE-FR02-04ER41300, National Science Foundation, Grant No. 0969100, The Grainger Foundation USA; NAFOSTED, Vietnam; ALFA-EC / HELEN, European Union 6th Framework Program, Grant No. MEIF-CT-2005-025057, European Union 7th Framework Program, Grant No. PIEF-GA-2008-220240 and UNESCO.
NO Unión Europea. FP7
NO Ministerio de Ciencia e Innovacion and Consolider-Ingenio (CPAN)
NO AVCR, Czech Republic
NO Centre de Calcul
NO Centre National de la Recherche Scientifique (CNRS)
NO Conseil Regional Ile-de-France, Departement Physique Nucleaire et Corpusculaire,  (PNC-IN2P3/CNRS)
NO Departement Sciences de l'Univers (SDU-INSU/CNRS), France
NO Bundesministerium fur Bildung und Forschung (BMBF)
NO Deutsche Forschungsgemeinschaft (DFG)
NO Finanzministerium Baden-Wurttemberg
NO Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF)
NO Ministerium fur Wissenschaft rind Forschung Nordrhein-Westfalen
NO Ministerium fur Wissenschaft, Forschung und Kunst, Baden-Wurttemberg, Germany
NO Istituto Nazionale di Fisica Nuclear (INFN)
NO Istituto Nazionale di Astrofisica (INAF)
NO Minister dell'Istruzione, dell'Universita e della Ricerca (MIUR)
NO Gran Sasso Center for Astroparticle Physics (CFA), Italy
NO Ministerie an Onderwijs, Cultuur en Wetenschap
NO Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
NO Stichting voor Fundamenteel Onderzoek der Materie (FOM), Netherlands
NO Ministry of Science and Higher Education, Poland
NO Fundacao para a Ciencia e a Tecnologia, Portugal
NO Ministry for Higher Education, Science, and Technology, Slovenian Research Agency, Slovenia
NO Comunidad de Madrid
NO Consejeria de Educacion de la Comunidad de Castilla La Mancha
NO FEDER funds
NO Generalitat Valenciana
NO Junta de Andalucia
NO Xunta de Galicia, Spain
NO Science and Technology Facilities Council, United Kingdom
NO Department of Energy
NO ALFA-EC / HELEN
NO Unión Europea. FP6
NO UNESCO
DS Docta Complutense
RD 6 abr 2025