Measuring inclined air showers with the upgraded Pierre Auger Observatory

by Felix Schlüter (Karlsruhe Institute of Technology)

Thursday 2 Dec 2021, 10:30 → 12:30 Europe/Stockholm

The Pierre Auger Observatory in the province of Mendoza, Argentina, is the world’s largest cosmic-ray air shower experiment, covering an area of 3000 km2.  It measures the spectrum of cosmic rays at energies well beyond 10e19 eV with unprecedented accuracy, utilizing different detector and detection techniques. After two decades of successful operation, the observatory is currently being upgraded to increase its mass-composition sensitivity. The AugerPrime upgrade includes the installation of a horizontal, di-polarized radio antenna on top of each of the 1661 water-Cherenkov detector stations. The coincident detection of very inclined air showers with radio and particle detectors provides an excellent mass sensitivity.

To exploit the full potential of the AugerPrime Radio Detector we developed a new reconstruction algorithm for extensive air showers with zenith angles between 65° and 85°. Our algorithm individually describes the dominant rotational symmetric geomagnetic emission and additional asymmetries introduced by the superposition of charge-excess and geomagnetic radiation as well as by geometrical early-late effects.

We will present the first results of an end-to-end simulation study of the performance of the AugerPrime Radio Detector.

The performance is evaluated utilizing a comprehensive set of simulated air showers together with recorded background. The estimation of an energy- and direction-dependent aperture yields an estimation of the expected 10-year event statistics. The potential to measure the number of muons in air showers with the achieved statistics is outlined. Based on the achieved energy resolution, the potential to discriminate between different cosmic-ray primaries is presented.