Correlation function of ultra-high energy cosmic rays favors point sources
P. G. Tinyakov, I. I. Tkachev
+Institute of Theoretical Physics, University of Lausanne, CH-1015 Lausanne, Switzerland *CERN Theory Division, CH-1211 Geneva 23, Switzerland Institute for Nuclear Research RAS, 117312 Moscow, Russia
PACS: 98.70.Sa
Abstract
We calculate the angular two-point correlation function of
ultra-high energy cosmic rays (UHECR) observed by AGASA and Yakutsk experiments.
In both data sets, there is a strong signal at highest energies, which
is concentrated in the first bin of the size of the angular resolution
of the experiment. For the uniform distribution of sources, the
probability of a chance clustering is 4•10-6. Correlations
are absent or not significant at larger angles. This favors the models
with compact sources of UHECR.
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