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  • J Abraham, P Abreu, M Aglietta, C Aguirre, D Allard, I Allekotte +439 others
  • 2007
Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above 6 x 10(19) electron volts and the positions of active galactic nuclei (AGN) lying within approximately 75 megaparsecs. We rejected the hypothesis of an isotropic distribution of these(More)
The Pierre Auger Observatory in Malargüe, 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(More)
  • J Abraham, M Aglietta, C Aguirre, D Allard, I Allekotte, P Allison +428 others
  • 2007
An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies greater than 10 19 eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This(More)
As old-growth forests are converted into edge-affected habitats, a substantial proportion of tropical biodiversity is potentially threatened. Here, we examine a comprehensive set of community-level attributes of fruit-feeding butterfly assemblages inhabiting edge-affected habitats in a fragmented Atlantic forest landscape devoted to sugar cane production.(More)
Resumo: Para a integração dos núcleos de um sistema integrado a uma NoC (Network-on-Chip), é necessário o uso de interfaces de comunicação que realizem a adaptação do protocolo dos núcleos ao da rede e que ofereçam os serviços de comunicação necessários aos núcleos. Este artigo descreve a arquitetura de uma interface de rede extensível para a integração de(More)
  • J Abraham, M Aglietta, C Aguirre, D Allard, I Allekotte, P Allison +430 others
  • 2007
Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the forerunner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR(More)
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