The flux of ultra-high-energy cosmic rays along the supergalactic plane measured at the Pierre Auger Observatory
Ultra-high-energy cosmic rays are known to be mainly of extragalactic origin, and their propagation is limited by energy losses, so their arrival directions are expected to correlate with the large-scale structure of the local Universe. In this work, we investigate the possible presence of intermedi...
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Format | Journal Article |
Language | English |
Published |
09.07.2024
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Subjects | |
Online Access | Get full text |
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Summary: | Ultra-high-energy cosmic rays are known to be mainly of extragalactic origin,
and their propagation is limited by energy losses, so their arrival directions
are expected to correlate with the large-scale structure of the local Universe.
In this work, we investigate the possible presence of intermediate-scale
excesses in the flux of the most energetic cosmic rays from the direction of
the supergalactic plane region using events with energies above 20 EeV recorded
with the surface detector array of the Pierre Auger Observatory up to 31
December 2022, with a total exposure of 135,000 km^2 sr yr. The strongest
indication for an excess that we find, with a post-trial significance of
3.1{\sigma}, is in the Centaurus region, as in our previous reports, and it
extends down to lower energies than previously studied. We do not find any
strong hints of excesses from any other region of the supergalactic plane at
the same angular scale. In particular, our results do not confirm the reports
by the Telescope Array collaboration of excesses from two regions in the
Northern Hemisphere at the edge of the field of view of the Pierre Auger
Observatory. With a comparable exposure, our results in those regions are in
good agreement with the expectations from an isotropic distribution. |
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DOI: | 10.48550/arxiv.2407.06874 |