Results of a self-triggered prototype system for radio-detection of extensive air showers at the Pierre Auger Observatory

THE PIERRE AUGER COLLABORATION (505 AUTHORS IN ALPHABETICAL ORDER); GARCÍA, B.

JOURNAL OF INSTRUMENTATION

IOP PUBLISHING LTD

Lugar: Londres; Año: 2012 vol. 7 p. 1 - 30

1748-0221

We describe the experimental setup and the results of RAuger, a small radio-antennaarray, consisting of three fully autonomous and self-triggered radio-detection stations, installedclose to the center of the Surface Detector (SD) of the Pierre Auger Observatory in Argentina. Thesetup has been designed for the detection of the electric field strength of air showers initiated byultra-high energy cosmic rays, without using an auxiliary trigger from another detection system.Installed in December 2006, RAuger was terminated in May 2010 after 65 registered coincidenceswith the SD. The sky map in local angular coordinates (i.e., zenith and azimuth angles) of theseevents reveals a strong azimuthal asymmetry which is in agreement with a mechanism dominatedby a geomagnetic emission process. The correlation between the electric field and the energy ofthe primary cosmic ray is presented for the first time, in an energy range covering two orders of magnitude between 0.1 EeV and 10 EeV. It is demonstrated that this setup is relatively more sensitive to inclined showers, with respect to the SD. In addition to these results, which underlinethe potential of the radio-detection technique, important information about the general behavior of self-triggering radio-detection systems has been obtained. In particular, we will discuss radio self-triggering under varying local electric-field conditions.