A search for point sources of EeV photons

Abstract

Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from -85° to +20°, in an energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.

28 pages, 10 figures, accepted for publication in The Astrophysical Journal

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• Teraelectronvolt Astronomy
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Cited by in corpus (7)

• Radio detection of Cosmic-Ray Air Showers and High-Energy Neutrinos
• Multi-Messenger Physics with the Pierre Auger Observatory
• A targeted search for point sources of EeV photons with the Pierre Auger Observatory
• Searches for Ultra-High-Energy Photons at the Pierre Auger Observatory
• Near-future discovery of point sources of ultra-high-energy neutrinos
• Multi-Resolution HEALPix Maps for Multi-Wavelength and Multi-Messenger Astronomy
• $F_{\gamma }$: a new observable for photon-hadron discrimination in hybrid air shower events