Learn More
Ultra high energy neutrinos are produced by the interaction of hadronic cosmic rays with the cosmic radiation background. More exotic scenarios like topological defects or new hadrons predict even larger fluxes. In particular, Earth–skimming tau neutrinos could be detected by the Fluorescence Detector (FD) of Pierre Auger Observatory. A detailed evaluation(More)
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)
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)
The determination of the primary cosmic ray mass composition from the longitudinal development of atmospheric cascades is still a debated issue. In this work we discuss several data analysis methods and show that if the entire information contained in the longitudinal profile is exploited, reliable results may be obtained. Among the proposed methods FCC(More)
Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with E ≥ 6×10 19 eV by analyzing cosmic rays with energies above E ≥ 5×10 18 eV arriving within an angular separation of approximately 15 •. We characterize the(More)
An event-by-event study, based on neural network method, of the mass identification in high energy cosmic rays was carried out with simulated data. Extensive air showers were simulated with the CONEX code, using the hadronic model QGSJET-II-3. The goodness of the method in recognizing the mass of the primary was tested making use of the parameters extracted(More)
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)
  • 1