RT Journal Article
T1 A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory
A1 Arganda, E.
A1 Arqueros Martínez, Fernando
A1 Blanco Ramos, Francisco
A1 García Pinto, Diego
A1 Minaya Flores, Ignacio Andrés
A1 Ortiz Ramis, Montserrat
A1 Rosado Vélez, Jaime
A1 Vázquez Peñas, José Ramón
AB Observations of cosmic rays arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Veron-Cetty Veron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three method can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. using data taken from January 1, 2004 to July 31, 2010 we examined the 20, 30, ... , 110 highest energy events with a corresponding minimum energy threshold of about 49.3 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.
PB IOP Publishing
SN 1475-7516
YR 2012
FD 2012-04
LK https://hdl.handle.net/20.500.14352/45079
UL https://hdl.handle.net/20.500.14352/45079
LA eng
NO © 2012 IOP Publishing Ltd and Sissa Medialab srlWe 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 KJB100100904, MSMT-CR LA08016, LC527, 1M06002, MEB111003, and MSM0021620859, Czech Republic; Centre de Calcul 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 und Forschung, Nordrhein-Westfalen, Ministerium fur Wissenschaft, Forschung und Kunst, Baden-Wurttemberg, Germany; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR), Italy; Consejo Nacional de Ciencia y Tecnologia (CONACYT), Mexico; Ministerie van 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. N N202 200239 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), 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. 0450696, The Grainger Foundation USA; 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 (MICINN)
NO Comunidad de Madrid
NO AVCR, Czech Republic
NO GAAV, Czech Republic
NO MSMT-CR, Czech Republic
NO Centre de Calcul IN2P3/CNRS, France
NO Centre National de la Recherche Scientifique (CNRS), France
NO Conseil Regional Ile-de-France, France
NO Departement Physique Nucleaire et Corpusculaire (PNC-IN2P3/CNRS), France
NO Departement Sciences de l'Univers (SDU-INSU/CNRS), France
NO Bundesministerium fur Bildung und Forschung (BMBF), Germany
NO Deutsche Forschungsgemeinschaft (DFG), Germany
NO Finanzministerium Baden-Wurttemberg, Germany
NO Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF), Germany
NO Ministerium fur Wissenschaft und Forschung, Germany Nordrhein-Westfalen, Germany
NO Ministerium fur Wissenschaft, Forschung und Kunst, Baden-Wurttemberg Germany
NO Istituto Nazionale di Fisica Nucleare (INFN), Italy
NO Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR), Italy
NO Ministerie van Onderwijs, Cultuur en Wetenschap, Netherlands
NO Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), Netherlands
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, Slovenia
NO Slovenian Research Agency, Slovenia
NO Consejeria de Educacion de la Comunidad de Castilla La Mancha, Spain
NO FEDER, Spain
NO Consolider-Ingenio (CPAN), Xunta de Galicia, Spain
NO Science and Technology Facilities Council, United Kingdom
NO ALFA-EC / HELEN
NO UNESCO
DS Docta Complutense
RD 10 may 2025