Centaurus A as a source of extragalactic cosmic rays with arrival energies well beyond the GZK cutoff

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The ultra--high energy cosmic rays recently detected by several air shower experiments could have an extragalactic origin. In this case, the nearest active galaxy Centaurus A might be the source of the most energetic particles ever detected on Earth. We have used recent radio observations in order to estimate the arrival energy of the protons accelerated by strong shock fronts in the outer parts of this southern radio source. We expect detections corresponding to particles with energies up to 2.2 × 10²¹ eV and an arrival direction of (l ≈ 310∘, b ≈ 20∘) in galactic coordinates. The future Southern Hemisphere Pierre Auger Observatory might provide a decisive test for extragalactic models of the origin of the ultra--high energy cosmic rays.