J. AbrahamP. AbreuM. AgliettaC. AguirreD. AllardI. AllekotteJ. AllenP. AllisonJaime Álvarez-MuñizM. Ambrosio2026-03-222026-03-22200810.1016/j.astropartphys.2008.01.003https://doi.org/10.1016/j.astropartphys.2008.01.003https://andeanlibrary.org/handle/123456789/43144Citaciones: 207enPierre Auger ObservatoryPhysicsAir showerCosmic rayAugerPhotonFlux (metallurgy)Ultra-high-energy cosmic rayObservatoryAstrophysicsUpper limit on the cosmic-ray photon flux above 1019eV using the surface detector of the Pierre Auger Observatoryarticle