Speaker
Description
The Pierre Auger Observatory, the largest air-shower experiment in the world designed to investigate ultra-high-energy (UHE, $E > 10^{17}$ eV) cosmic rays, offers unparalleled sensitivity to UHE photons. They are expected to originate from the interaction of UHE cosmic rays with background radiation fields, as well as from more exotic processes like the decay of hypothetical super-heavy dark matter particles. Moreover, UHE photons may be produced at cosmic-ray sources, making their detection instrumental in enhancing our multimessenger understanding of the cosmic-ray acceleration mechanisms and transient astrophysical phenomena.
Photon searches at the Pierre Auger Observatory leverage high-quality data acquired by the surface detector array, consisting of over $1660$ water-Cherenkov detectors spread across 3000 km$^2$, complemented by a fluorescence detector with $27$ telescopes overlooking it and, in a part of the array, an underground muon detector. In this contribution, we present recent results of photon searches above $10^{16.7}$ eV obtained with data collected before the AugerPrime upgrade. Additionally, we discuss photon searches conducted in coincidence with gravitational wave events detected by LIGO/Virgo, highlighting the pivotal role of the Observatory in advancing multi-messenger astronomy at the highest energies.
