Search for PeVatrons at the Galactic Center using a radio air-shower array at the South Pole

TL;DR

This paper explores using radio antennas at the South Pole to detect PeV gamma-ray air showers from the Galactic Center, aiming to lower energy detection thresholds and enable continuous observation.

Contribution

It proposes an optimized radio detection method to identify high-inclination PeV gamma-ray showers from the Galactic Center at the South Pole.

Findings

Radio detection can identify PeV gamma-ray showers.

Optimization of frequency band improves signal-to-noise ratio.

Potential for 24/7 observation of Galactic Center gamma rays.

Abstract

The South Pole, which hosts the IceCube Neutrino Observatory, has a complete and around-the-clock exposure to the Galactic Center. Hence, it is an ideal location to search for gamma rays of PeV energy coming from the Galactic Center. However, it is hard to detect air showers initiated by these gamma rays using cosmic-ray particle detectors due to the low elevation of the Galactic Center. The use of antennas to measure the radio footprint of these air showers will help in this case, and would allow for a 24/7 operation time. So far, only air showers with energies well above 10 PeV have been detected with the radio technique. Thus, the energy threshold has to be lowered for the detection of gamma-ray showers of PeV energy. This can be achieved by optimizing the frequency band in order to obtain a higher level of signal-to-noise ratio. With such an approach, PeV gamma-ray showers with high inclination can be measured at the South Pole.