Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2009-01-31
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
6 pages, 8 figures, Contributed to 21th ECRS, Kosice, Slovakia, 2008
Scientific paper
An anisotropy signal for the arrival directions of ultra-high energy cosmic rays (UHECR) of more than 99% confidence level was established using data collected by the Pierre Auger Observatory. Cosmic rays with energy above $\sim 6 \times 10^{19}$ eV show a correlation with the positions of extragalactic nearby active galactic nuclei (AGN), being maximum for sources at less than $\sim$100 Mpc and angular separation of a few degrees. The evolution of the correlation signal with the energy shows that the departure from anisotropy coincides with the flux suppression observed in the spectrum, being therefore consistent with the hypothesis that the correlated events have their origin in extragalactic sources close enough to avoid significant interaction with the cosmic microwave background (the Greisen-Zatsepin-Kuz'min effect). Even though the observed signal cannot unambiguously identify AGNs as the production sites of UHECRs, the potential sources have to be distributed in a similar way. A number of additional statistical tests were performed in order to further understand the nature of the correlation signal.
Auger Colaboration for the Pierre
Santos Edivaldo M.
No associations
LandOfFree
Anisotropy Studies with the Pierre Auger Observatory does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Anisotropy Studies with the Pierre Auger Observatory, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Anisotropy Studies with the Pierre Auger Observatory will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-663100