Search for photons with energies above 10^18 eV using the hybrid detector of the Pierre Auger Observatory - Aab, A.; Albuquerque, Ivone Freire da Mota e; Souza, Vitor de; Anjos, R. C. dos; Gouffon, Philippe; Prado, R. R.; Santos, Edivaldo Moura; Peixoto, Carlos Jose Todero (Journal of Cosmology and Astroparticle Physics, 2017)