The Energy Content of Extensive Air Showers in the Radio Frequency Range of 30-80 MHz

摘要

At the Auger Engineering Radio Array (AERA) of the Pierre AugerObservatory, we have developed a new method to measure the total amount of energy that is transferred from the primarycosmic ray into radio emission. We find that this radiationenergy is an estimator of the cosmic ray energy. It scales quadratically with the cosmic ray energy, as expected for coherent emission. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicular to the geomagneticfield at the Auger site, in the frequency band of the detectorfrom 30 to 80 MHz. These observations are compared to the data of the surface detector of the Observatory, which provide well-calibrated energies and arrival directions of the cosmic rays. We find energy resolutions of the radio reconstruction of 22% for the complete data set, and 17% for a high-qualitysubset containing only events with at least five stations withsignal.