1,751 research outputs found
Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory
No full textA promising energy range to look for angular correlations between cosmic rays of extragalactic origin and their sources is at the highest energies, above a few tens of EeV (1 EeV ≡ 1018 eV). Despite the flux of these particles being extremely low, the area of ∼3000 km2 covered at the Pierre Auger Observatory, and the 17 yr data-taking period of the Phase 1 of its operations, have enabled us to measure the arrival directions of more than 2600 ultrahigh-energy cosmic rays above 32 EeV. We publish this data set, the largest available at such energies from an integrated exposure of 122,000 km2 sr yr, and search it for anisotropies over the 3.4π steradians covered with the Observatory. Evidence for a deviation in excess of isotropy at intermediate angular scales, with ∼15° Gaussian spread or ∼25° top-hat radius, is obtained at the 4σ significance level for cosmic-ray energies above ∼40 EeV.Fil: Abreu, P.. Instituto Superior Tecnico; Portugal. Universidade Nova de Lisboa; PortugalFil: Aglietta, M.. Istituto Nazionale di Astrofisica; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Albury, J.M.. University of Adelaide; AustraliaFil: Allekotte, Ingomar. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Mollerach, Maria Silvia. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro. Archivo Histórico del Centro Atómico Bariloche e Instituto Balseiro | Universidad Nacional de Cuyo. Instituto Balseiro. Archivo Histórico del Centro Atómico Bariloche e Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Almeida Cheminant, K.. Polish Academy Of Sciences; PoloniaFil: Zapparrata, O.. Université Libre de Bruxelles; BélgicaFil: Zas, E.. Universidad de Santiago de Compostela; EspañaFil: Zavrtanik, D.. University of Nova Gorica; Eslovaquia. Experimental Particle Physics Department; EslovaquiaFil: Zavrtanik, M.. University of Nova Gorica; Eslovaquia. Experimental Particle Physics Department; EslovaquiaFil: Zehrer, L.. University of Nova Gorica; Eslovaqui
Erratum to “Atmospheric effects on extensive air showers observed with the surface detector of the Pierre Auger observatory” [Astroparticle Physics 32(2) (2009), 89-99]
No full textThe affiliations were incorrectly published in the original version of this article for the following authors D. Allard, J.A. Bellido, R.M. Kieckhafer, L. Nellen, R. Pelayo, I. Rodriguez-Cabo, B.E. Smith, D. Veberic, L. Wiencke, D. Zavrtanik and M. Zavrtanik which has been corrected now.Este documento es una errata de "Atmospheric effects on extensive air showers observed with the surface detector of the Pierre Auger Observatory" (ver "Documentos relacionados").La lista completa de autores puede verse en el archivo asociado.Instituto de Física La Plat
The Lidar system of the Pierre Auger Observatory
No full textThe Pierre Auger Observatory in Malargue, Argentina, is designed to study the origin of ultrahigh energy cosmic rays with energies above 10(18) eV. The energy calibration of the detector is based on a system of four air fluorescence detectors. To obtain reliable calorimetric information from the fluorescence stations, the atmospheric conditions at the experiment's site need to be monitored continuously during operation. One of the components of the observatory's atmospheric monitoring system is a set of four elastic backscatter lidar stations, one station at each of the fluorescence detector sites. This paper describes the design, current status, standard operation procedure, and performance of the lidar system of the Pierre Auger Observatory. (c) 2007 Elsevier B.V. All rights reserved
A review of the latest CPLEAR results on T violation and CPT invariance in the neutral-kaon system
No full textDevelopment of a low-noise preamplifier for the detection of single electrons in Cerenkov ring imaging detectors
No full textAtmospheric aerosol monitoring at the Pierre Auger Observatory
No full textFor a ground based cosmic-ray observatory the atmosphere is an integral part of the detector. Air fluorescence detectors (FDs) are particularly sensitive to the presence of aerosols in the atmosphere. These aerosols,
consisting mainly of clouds and dust, can strongly affect the propagation of fluorescence and Cherenkov light
from cosmic-ray induced extensive air showers. The Pierre Auger Observatory has a comprehensive program
to monitor the aerosols within the atmospheric volume of the detector. In this paper the aerosol parameters
that affect FD reconstruction will be discussed. The aerosol monitoring systems that have been deployed at the
Pierre Auger Observatory will be briefly described along with some measurements from these systems
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