Observation of a large-scale anisotropy in the arrival directions of cosmic rays above 8 x 10¹⁸ eV

Cosmic rays are atomic nuclei arriving from outer space that reach the highest energies observed in nature. Clues to their origin come from studying the distribution of their arrival directions. Using 3 x 10⁴ cosmic rays with energies above 8 x 10¹⁸ electron volts, recorded with the Pierre Auger Obs...

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Detalles Bibliográficos
Autores: Arqueros Martínez, Fernando, García Pinto, Diego
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/18336
Acceso en línea:https://hdl.handle.net/20.500.14352/18336
Access Level:acceso abierto
Palabra clave:539.1
Multidisciplinary sciences
Electricidad
Electrónica (Física)
Física nuclear
2202.03 Electricidad
2207 Física Atómica y Nuclear
Descripción
Sumario:Cosmic rays are atomic nuclei arriving from outer space that reach the highest energies observed in nature. Clues to their origin come from studying the distribution of their arrival directions. Using 3 x 10⁴ cosmic rays with energies above 8 x 10¹⁸ electron volts, recorded with the Pierre Auger Observatory from a total exposure of 76,800 km(2) sr year, we determined the existence of anisotropy in arrival directions. The anisotropy, detected at more than a 5.2σ level of significance, can be described by a dipole with an amplitude of (6.5)_(-0.9)^(+1.3) % toward right ascension α_(d) = 100 ± 10 degrees and declination δ_(d) = -24_(-13)(+12) degrees. That direction indicates an extragalactic origin for these ultrahighenergy particles.