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arXiv · 2609.21105

The Auger Radio Infill SKALA Extension (ARISE): First Air-Shower Measurements

Carmen Merx for the Pierre Auger Collaboration
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Abstract

The Auger Radio Infill SKALA Extension (ARISE) was installed at the Pierre Auger Observatory in 2025 to detect the radio emission in the band of $50-350\,$MHz of near-vertical cosmic-ray air showers of energies around and above $100\,$PeV. The array comprises 18 SKALA~v2 antennas deployed around one of the surface-detector stations of the $433\,$m array (SD-433), which provides the trigger for ARISE. We present first measurements with ARISE and show the detection of radio pulses associated with extensive air showers. Radio signals are found in coincidence with SD-433 events, and a comparison of the arrival directions reconstructed from the radio and surface detector signals confirms the measurement of air showers with ARISE. These observations provide a first assessment of the detector setup and demonstrate the potential of ARISE for radio detection of near-vertical air showers.

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Carmen Merx for the Pierre Auger Collaboration. 2026-09-17. The Auger Radio Infill SKALA Extension (ARISE): First Air-Shower Measurements. https://doi.org/10.22323/1.538.0009

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