The Directional Dependence of the Lunar Cherenkov Technique for UHE Neutrino Detection

TL;DR

This paper investigates how the lunar Cherenkov technique's sensitivity to ultra-high-energy neutrinos varies with direction, highlighting anisotropies and optimizing future observations with the SKA.

Contribution

It provides simulation-based analysis of directional dependence and sky coverage for lunar Cherenkov UHE neutrino detection, informing optimal observation strategies.

Findings

Sensitivity is highly anisotropic across the sky.

Certain regions remain unprobed by current experiments.

Future SKA observations can maximize sensitivity through strategic pointing.

Abstract

The LUNASKA (Lunar UHE Neutrino Astrophysics with the Square Kilometre Array) project is a theoretical and experimental project developing the lunar Cherenkov technique for the next generation of giant radio-telescope arrays. This contribution presents our simulation results on the directional dependence of the technique for UHE neutrino detection. In particular, these indicate that both the instantaneous sensitivities and time-integrated limits from lunar Cherenkov experiments such as those at Parkes, Goldstone, Kalyazin and ATCA are highly anisotropic. We study the regions of the sky which have not been probed by either these or other experiments, and present the expected sky coverage of future experiments with the SKA. Our results show how the sensitivity of Lunar Cherenkov observations to potential astrophysical sources of UHE particles may be maximised by choosing appropriate observations dates and antenna-beam pointing positions.