Naslov
Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

Autori
Abreu, P. ; ... ; Antičić, Tome ; ... ; Kadija, Krešo ; ... ; Mićanović, Saša ; ... ; Šuša, Tatjana ; ... ; Ziolkowski, M.

Izvornik
Journal of cosmology and astroparticle physics (1475-7516) (2011), Astro-ph/1106.3048; 1-15

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
ultra high energy cosmic rays; cosmic ray experiments

Sažetak
The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > Eth = 5.5×10^19 eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > Eth are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above Eth/Z (for illustrative values of Z = 6, 13, 26). If the anisotropies above Eth are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
The Pierre Auger Collaboration

POVEZANOST RADA