The dawn of the particle astronomy era in ultra-high-energy cosmic rays


Cosmic rays are charged particles arriving at the Earth from space. Those at the highest energies are particularly interesting because the physical processes that could create or accelerate them are at the limit of our present knowledge. They also open the window to particle astronomy, as the magnetic fields along their paths are not strong enough to deflect their trajectories much from a straight line. The Pierre Auger Observatory is the largest cosmic-ray detector on Earth, and as such is beginning to resolve past observational disagreements regarding the origin and propagation of these particles.

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Figure 1: Scheme of an extensive air-shower.
Figure 2: UHECR data from different experiments.
Figure 3: The Pierre Auger Southern Observatory.
Figure 4: Hillas diagram.


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We express our gratitude to many people, too many to mention individually, in the AMANDA and Auger Collaborations, who guided us through the cosmic-ray world over the years. We especially thank our mentor A. Filevich, whom introduced us to cosmic-ray physics and the scientific world.

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Correspondence to Pablo M. Bauleo.

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Bauleo, P., Martino, J. The dawn of the particle astronomy era in ultra-high-energy cosmic rays. Nature 458, 847–851 (2009).

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