This is still an open question in astroparticle physics and a long-standing mystery that the Pierre Auger Observatory aims to solve.
Scientific Highlights
Understanding the origin and nature of ultra-high energy cosmic rays has been one of the driving forces of the field of astroparticle physics. A key piece of information is what type of particles cosmic rays consist of.
For the first time, the possible appearance of ultra-high energy photons from merging compact objects such as black holes was tested.
The energy spectrum and mass composition data from the Pierre Auger Observatory constrain the source properties.
The latest data of the Pierre Auger Observatory constrains scenarios of super-heavy particle relics.
In a recent review article current searches for ultra-high-energy (UHE) photons at the Pierre Auger Observatory were summarized.