Search for Ultra-High Energy Photons with the Pierre Auger Observatory
  The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture for the search of photons with energy above 100 PeV. In this contribution recent results are presented including the diffuse search for photons and the directional search for photon point sources. The derived limits are of considerable astrophysical interest: Diffuse limits place severe constraints on top-down models and start to touch the predicted GZK photon flux range while directional limits can exclude the continuation of the electromagnetic flux from measured TeV sources with a significance of more than 5$\sigma$. Finally, prospects of neutral particle searches for the upcoming detector upgrade AugerPrime are highlighted. 
Daniel Kuempel (for the Pierre Auger Collaboration)
astro-ph.HE