Speaker
Description
In its Phase I, the Pierre Auger Observatory has led to several observations, driving the field of ultra-high-energy cosmic ray (UHECR) research over the last 20 years. Major achievements obtained so far include the unprecedented precise energy spectrum and its features, the observables linked to the UHECR mass composition and the distribution of arrival directions of the most energetic events. These results, together with the non-observation of high-energy neutrinos and photons, strongly contribute to move away from the pure-proton paradigm which was mainly accepted at the time of the conception of the Observatory.
In this talk, we will provide an overview on the main results of the Observatory together with the astrophysical scenarios that produce a global and consistent interpretation of data. We will also assess the level of exclusion of other alternative scenarios, in particular the pure-proton composition. The prospects of improving the current understanding about UHECR characteristics during the Phase II of the Observatory will be also shown.