Ponente
Descripción
The Pierre Auger Observatory, the largest air-shower detector in the world, provides unmatched exposure to photons with energies above 5 × 10¹⁶ eV. Its hybrid detection system - combining a surface detector array and fluorescence telescopes - enables the most stringent upper limits on the diffuse Ultra-High-Energy photon flux, achieved through advanced discrimination of photon-induced air showers and hadron-induced air showers. These limits, derived from nearly two decades of data, challenge theoretical models of cosmic-ray origins, including top-down scenarios and extreme astrophysical accelerators, and also highlight the significant capabilities of the Pierre Auger Observatory in the framework of multi-messenger astronomy at the highest energies. In this contribution, we present the latest Auger Observatory results on photon searches and review prior follow-up investigations of photons associated with gravitational wave events that LIGO/Virgo detected. Finally, we discuss the impact of AugerPrime, the upgrade of the Pierre Auger Observatory, on photon searches by further increasing the sensitivity, thus continuing to play a key role in gaining new insights on the most extreme phenomena in the Universe.
