Detection of Ultra High Energy Cosmic Rays and Neutrinos with Lunar Orbital Radio Telescope

TL;DR

This paper explores the potential of lunar orbiting ultra-long wavelength radio telescopes to detect Cherenkov radio emissions caused by ultra-high-energy cosmic rays and neutrinos impacting the Moon's surface, aiding future lunar radio missions.

Contribution

It presents instrument modeling and analysis demonstrating the feasibility of detecting and reconstructing UHE cosmic ray and neutrino events using lunar orbiting ULW radio antennas.

Findings

Cherenkov radiation is detectable with lunar orbit radio telescopes.

Cosmic ray and neutrino events can be reconstructed via polarization and pulse measurements.

The study supports future lunar radio exploration for UHE particle detection.

Abstract

Particle cascades induced by ultra-high-energy (UHE) cosmic rays and neutrinos impacting on the lunar regolith usually radiate Cherenkov radio emissions due to the presence of excess negative charge, which is known as Askaryan effect. Several experiments have been carried out to detect the Cherenkov radio emissions in the lunar regolith. To prepare for future lunar Ultra-Long Wavelength (ULW, frequencies below 30 MHz) radio astronomy missions, we study the detection of the Cherenkov radio emissions with the ULW radio telescope that are operating at the lunar orbit. We have carried out instrument modelling and analytic calculations for the analysis of aperture, flux and event rate, and the analyses show the detectability of the Cherenkov radiation. Based on the properties of the Cherenkov radiation, we have demonstrated that the cosmic ray and neutrino events could be reconstructed with the three ULW vector antennas onboard the lunar satellites via measurements of the Askaryan radio pulse intensity, polarizations, etc. The results obtained by this study would be useful for future lunar radio explorer mission, where the detections of UHE cosmic rays and neutrinos could be successfully attempted.