2006/03/22 by Daniel De Marco, Pasquale Blasi, Angela V. Olinto +1 · 6 citations
Physics and Astronomy · #Anisotropy #Astrophysics and Cosmic Phenomena #Auger #Cosmic ray #Dark Matter and Cosmic Phenomena #Galaxy #Isotropy #Normalization (sociology) #Particle physics theoretical and experimental studies #Pierre Auger Observatory #Range (aeronautics) #Spectral density #astro-ph
paper · pdf · doi:10.1088/1475-7516/2006/07/015
published in Journal of Cosmology and Astroparticle Physics 2006(07), 015 (Institute of Physics) · 15 pages, 6 figures, 6 tables, submitted to JCAP
arxiv created 2006/03/22 · openalex publication_date 2006/07/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the small scale anisotropy signal expected at the Pierre Auger Observatory after 1, 5, 10, and 15 years of operation, from sources of ultra-high energy (UHE) protons. We numerically propagate UHE protons over cosmological distances using an injection spectrum and normalization that fits current data up to ∼10 20 eV. We characterize possible sources of ultra-high energy cosmic rays (UHECRs) by their mean density in the local universe, , with r between 3 and 6. These densities span a wide range of extragalactic sites for UHECR sources, from common to rare galaxies or even clusters of galaxies. We simulate 100 realizations for each model and calculate the two point correlation function for events with energies above 4 × 10 19 eV and above 10 20 eV with the exposure of the Auger South Observatory. We find that for , Auger should be able to detect small scale anisotropies in the near future. Distinguishing between different source densities based on cosmic ray data alone will be more challenging than detecting a departure from isotropy and is likely to require larger statistics of events. Combining the angular distribution studies with the spectral shape around the GZK feature will also help distinguish between different source scenarios.