AugerPrime: the Pierre Auger Observatory Upgrade

The world largest exposure to ultra-high energy cosmic rays accumulated by the Pierre Auger Observatory led to major advances in our understanding of their properties, but the many unknowns about the nature and distribution of the sources, the primary composition and the underlying hadronic interactions prevent the emergence of a uniquely consistent picture. The new perspectives opened by the current results call for an upgrade of the Observatory, whose main aim is the collection of new information about the primary mass of the highest energy cosmic rays on a shower-by-shower basis. The evaluation of the fraction of light primaries in the region of suppression of the flux will open the window to charged particle astronomy, allowing for composition-selected anisotropy searches. In addition, the properties of multiparticle production will be studied at energies not covered by man-made accelerators and new or unexpected changes of hadronic interactions will be searched for. After a discussion of the motivations for upgrading the Pierre Auger Observatory, a description of the detector upgrade is provided. We then discuss the expected performances and the improved physics sensitivity of the upgraded detectors and present the first data collected with the already running Engineering Array.Comment: 9 pages, 11 figures, presented at UHECR 2018 (Paris, Oct 2018

Astroparticle and particle physics at ultra-high energy: results from the Pierre Auger Observatory

The scientific achievements of the Pierre Auger Collaboration cover diverse and complementary fields of research. The search for the origin of ultra-high energy cosmic rays (UHECRs) is based on the measurement of the energy spectrum and mass composition of the primaries, on studies of multi-messengers, and on extensive anisotropy searches. With the collected data it is also possible to explore the characteristics of hadronic interactions at energies unreachable at human-made accelerators, and to assess the existence of non-standard physics effects. A selection of the latest results is presented and the emerging picture is discussed.Comment: Submission to SciPost Phys. Pro

Auger Highlights

The Pierre Auger Observatory has been designed to investigate the origin and nature of the ultra high energy cosmic rays using a hybrid detection technique. A review of selected results is presented, with the emphasis given to the measurement of energy spectrum, mass composition and arrival directions

Astroparticelle di altissima energia

La fisica astro-particellare è un campo interdisciplinare giovane, che studia la radiazione e le particelle del cosmo utilizzando tecniche tipiche degli esperimenti di alta energia. Alcune di queste particelle cosmiche raggiungono energie incredibilmente elevate, ed il loro studio è uno degli argomenti più affascinanti dell'astrofisica moderna. Questi messaggeri ultra-energetici dallo spazio profondo possono raggiungere la Terra ed essere osservati con apparati sperimentali dedicati e ci forniscono informazioni ineguagliabili sulle loro sorgenti e sulla struttura dell'Universo

Astroparticelle di altissima energia

La fisica astro-particellare è un campo interdisciplinare giovane, che studia la radiazione e le particelle del cosmo utilizzando tecniche tipiche degli esperimenti di alta energia. Alcune di queste particelle cosmiche raggiungono energie incredibilmente elevate, ed il loro studio è uno degli argomenti più affascinanti dell'astrofisica moderna. Questi messaggeri ultra-energetici dallo spazio profondo possono raggiungere la Terra ed essere osservati con apparati sperimentali dedicati e ci forniscono informazioni ineguagliabili sulle loro sorgenti e sulla struttura dell'Universo

Search for Extreme Energy Cosmic Rays with the TUS orbital telescope and comparison with ESAF

The Tracking Ultraviolet Setup (TUS) detector was launched on April 28, 2016 as a part of the scientific payload of the Lomonosov satellite. TUS is a pathfinder mission for future space-based observation of Extreme-Energy Cosmic Rays (EECRs, E > 5x1019 eV) with experiments such as K-EUSO. TUS data offer the opportunity to develop strategies in the analysis and reconstruction of the events which will be essential for future space-based missions. During its operation, TUS has detected about 80 thousand events which have been subject to an offline analysis to select among them those that satisfy basic temporal and spatial criteria of EECRs. A few events passed this first screening. In order to perform a deeper analysis of such candidates, a dedicated version of ESAF (EUSO Simulation and Analysis Framework) code as well as a detailed modelling of TUS optics and detector are being developed

The Pierre Auger Cosmic Ray Observatory

The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above 1017 eV and to study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water Cherenkov particle detector stations spread over 3000 km2 overlooked by 24 air fluorescence telescopes. In addition, three high elevation fluorescence telescopes overlook a 23.5 km2, 61-detector infilled array with 750 m spacing. The Observatory has been in successful operation since completion in 2008 and has recorded data from an exposure exceeding 40,000 km2 sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Observatory

Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accuracy by this correction. First, we operate a ``beacon transmitter'' which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA. <P /