Accessing the Cosmic-Ray Energy Scale with the Auger Engineering Radio Array

The Pierre Auger Observatory is the largest ground-based observatory for the detection of extensive particle showers in air induced by ultra-high energy cosmic rays. It is situated in the Argentinian Pampa near the city of Malargüe. Multiple different detectors are operated and allow for hybrid measurements of the same shower. An absolute calibration of the reconstructed cosmic-ray energies is determined with the fluorescence detector (FD) and transferred to the surface detector (SD) through cross-calibrations.

The radio detection of air showers provides an independent access to the cosmic-ray energy scale. At the Pierre Auger Observatory, the radio detection is so far performed with the Auger Engineering Radio Array (AERA), and within the next year will be extended to the highest energies with the upcoming Radio Detector. The hybrid detector environment allows to compare the energy scales set by FD and AERA. In this contribution, we show how we can independently determine the cosmic-ray energy scale at the Pierre Auger Observatory with hybrid measurements from AERA and SD.

*This research was supported by the Bundesministerium für Bildung und Forschung (BMBF) under the contract 05A20VK1.