Related papers: An upper limit to photons from first data taken by…
The Pierre Auger Observatory has a unique potential to search for ultra-high energy photons (above ~1 EeV). First experimental limits on photons were obtained during construction of the southern part of the Observatory. Remarkably, already…
A method is developed to search for air showers initiated by photons using data recorded by the surface detector of the Auger Observatory. The approach is based on observables sensitive to the longitudinal shower development, the signal…
One of key scientific objectives of the Pierre Auger Observatory is the search for ultra-high energy photons. Such photons could originate either in the interactions of energetic cosmic-ray nuclei with the cosmic microwave background…
The Pierre Auger Observatory is the largest air-shower detector in the world, offering unparalleled exposure to photons with energies above $5 \times 10^{16}$ eV. Since the start of data collection almost two decades ago, numerous searches…
The observation of photons with energies above 10^18 eV would open a new window in cosmic-ray research, with possible impact on astrophysics, particle physics, cosmology and fundamental physics. Current and planned air shower experiments,…
Based on observations of the depth of shower maximum performed with the hybrid detector of the Auger Observatory, an upper limit on the cosmic-ray photon fraction of 26% (at 95% confidence level) is derived for primary energies above 10^19…
Data taken at the Pierre Auger Observatory are used to search for air showers initiated by ultra-high energy (UHE) photons. Results of searches are reported from hybrid observations where events are measured with both fluorescence and array…
From direct observations of the longitudinal development of ultra-high energy air showers performed with the Pierre Auger Observatory, upper limits of 3.8%, 2.4%, 3.5% and 11.7% (at 95% c.l.) are obtained on the fraction of cosmic-ray…
We report a calculation of the expected rate of inclined air showers induced by ultra high energy cosmic rays to be obtained by the Auger Southern Observatory assuming different mass compositions. We describe some features that can be used…
The first interactions of photon-induced showers are of electromagnetic nature, and the transfer of energy to the hadron/muon channel is reduced with respect to the bulk of hadron-induced showers. This results in a lower number of secondary…
An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies greater than 10^19 eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger…
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…
A search for ultra-high energy photons with energies above 1 EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries…
Astroparticles offer a new path for research in the field of particle physics, allowing investigations at energies above those accesible with accelerators. Ultra-high energy cosmic rays can be studied via the observation of the showers they…
We present a new method to derive an upper limit on the ultra-high-energy (UHE) photon flux above a given energy, using the Auger SD events. As previous studies, it takes advantage of the fundamental differences between showers induced by…
The Pierre Auger Observatory has been designed to investigate the most energetic particles known, the ultra high energy cosmic rays. The observatory, covering an area of 3000 km^2, combines two different detection techniques to study the…
In this paper, the connection between Pierre Auger Observatory measurements and photons is discussed. Three cases are presented: the search for photons in the ultrahigh-energy cosmic-ray radiation, the impact of the photon background in the…
We consider the ultra-high energy cosmic ray (UHECR) spectrum as measured by the Pierre Auger Observatory. Top-down models for the origin of UHECRs predict an increasing photon component at energies above about $10^{19.7}$eV. Here we…
The Pierre Auger Observatory has already collected more ultra high energy cosmic ray data than all the previous experiments. With an hybrid detection technique, it can provide coherent results on the flux, energy spectrum and arrival…
The Pierre Auger Observatory is the largest astroparticle experiment in operation. Complementary to the measurements of the charged ultra-high energy (UHE) cosmic rays, it provides a very good sensitivity to the detection of UHE photons and…