The Hybrid Elevated Radio Observatory for Neutrinos (HERON) Project

TL;DR

HERON is a proposed large-scale radio observatory designed to detect ultra-high energy neutrinos above 10^{16} eV, combining innovative radio detection techniques for enhanced sensitivity and angular resolution in the multi-messenger astronomy era.

Contribution

HERON introduces a novel hybrid radio detection system combining phased stations and standalone antennas for ultra-high energy neutrino detection.

Findings

Preliminary design of HERON with 24 phased stations and 360 standalone antennas.

Expected energy threshold below 100 PeV for neutrino detection.

Enhanced sensitivity and reconstruction capabilities for astrophysical neutrino sources.

Abstract

Measuring ultra-high energy neutrinos, with energies above $10^{16}$ eV, is the next frontier of the emerging multi-messenger era. Their detection requires building a large-scale detector with 10 times the instantaneous sensitivity of current instruments, sub-degree angular resolution, and wide daily field of view. The Hybrid Elevated Radio Observatory for Neutrinos (HERON) is designed to be that discovery instrument. HERON combines the complementary features of two radio techniques being demonstrated by the BEACON and GRAND prototypes. Its preliminary design consists of 24 compact, elevated phased stations with 24 antennas each, embedded in a sparse array of 360 standalone antennas. This setup tunes the energy threshold to below 100 PeV, where the neutrino flux should be high. The sensitivity of the phased stations combines with the powerful reconstruction capacities of the standalone antennas to produce an optimal detector. HERON is planned to be installed at an elevation of 1,000 m across a 72 km-long mountain range overlooking a valley in Argentina's San Juan province. It would be connected to the worldwide network of multimessenger observatories and search for neutrino bursts from candidate sources of cosmic rays, like gamma-ray bursts and other powerful transients. With HERON's deep sensitivity, this strategy targets discoveries that cast new light into the inner workings of the most violent astrophysical sources at uncharted energies. We present the preliminary design, performances, and observation strategy of HERON.