Home

Hybrid Detector

The hybrid nature of the Pierre Auger Observatory provides for two independent ways to see cosmic rays. Read More...

Time Lapse Video

Who Was Pierre Auger?

The Pierre Auger Observatory experiment was named after Pierre Victor Auger (1899 - 1993) Read More...

Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory

Cosmic rays are mostly charged particles that reach Earth from outer space. Although they were discovered more than a century ago, the origin of the ultra-high energy ones (with an energy above 10¹⁸ eV, or 100,000 times more energetic than the particles in the LHC beam, the most powerful particle accelerator on Earth) is still a puzzle. The large area of the Pierre Auger Observatory of about 3000 km² compensates for the low flux of such particles and allows us to search for an excess/deficit of events arriving from different directions in the celestial sphere.

Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

The Pierre Auger Collaboration has investigated the constraining power of the cosmic ray spectrum and composition measurements with respect to the properties of the possible sources.

Search for photons above 10^18 eV with the hybrid detector of the Pierre Auger Observatory

The Pierre Auger Collaboration has searched for the possible presence of photons with energies exceeding 10¹⁸ eV in the flux of cosmic rays arriving at Earth. These ultra-high energy photons are produced in interactions of the charged cosmic rays with energies close to 10²⁰ eV with the cosmic microwave background (GZK effect).

Impact of atmospheric effects on the energy reconstruction of air showers observed by the surface detectors of the Pierre Auger Observatory

When an ultrahigh-energy cosmic ray impacts the Earth’s atmosphere, it can generate an enormous cascade of billions of energetic particles capable of reaching the ground. Such a cascade is dubbed an “extensive air shower” (EAS) and is routinely being detected by the Pierre Auger Observatory in Argentina near the city of Malargüe, using an array of surface detectors deployed over 3000 km².

Search for photon point sources at the Pierre Auger Observatory

One of the most pressing mysteries in astroparticle physics is the composition and origin of cosmic rays at energies around 1 EeV = 10¹⁸ eV. In contrast to charged particles, deflected in galactic and extragalactic magnetic fields, neutral particles such as neutrinos, neutrons, or photons point back to their production site. One way to learn more about sources of ultra-high energy cosmic rays is therefore to search for an accumulation of events from specific directions. This is akin to astronomical observations of a distant galaxy, say, made with an optical telescope collecting photons of visible light.

A Search for Ultrahigh-Energy Neutrinos in Auger data in Coincidence with Gravitational Waves

100 years after their prediction by Albert Einstein, Gravitational Waves (GW) were detected in 2015 by the LIGO detectors. With the surface detector of Auger we have searched for ultrahigh-energy neutrinos in temporal and spatial coincidence with such remarkable events.