Probing neutrino emission at GeV energies from astrophysical transient events with the IceCube Neutrino Observatory

TL;DR

This paper reports the first search for sub-5 GeV neutrinos from a gamma-ray burst using IceCube, focusing on GRB 221009A, and discusses plans to enhance detection capabilities for future transient events.

Contribution

It introduces a novel low-energy neutrino search in IceCube for astrophysical transients and presents initial results from GRB 221009A, along with planned improvements.

Findings

First < 5 GeV neutrino search from a GRB with IceCube

Detection strategies for low-energy neutrinos are being developed

Future plans include improved direction reconstruction and noise rejection

Abstract

Astrophysical transient events like Gamma Ray Bursts (GRBs) have always been promising candidates for multi-messenger astronomy, with electromagnetic and gravitational wave signals having already been observed in GRBs such as GRB 170817A. The neutrino signatures of these bursts have been long-awaited as well, with many models predicting different spectra. Most of these searches have been in the hundreds of GeV to PeV range. However, as different models indicate a possible lower energy neutrino signal, we intend to expand this search to the lowest limits of IceCube (0.5-5 GeV) as well. With the plan to look at more transient events, we present the result of the first IceCube search for < 5 GeV astrophysical neutrinos emitted from a GRB, for GRB 221009A; the brightest GRB ever observed. Furthermore, we present plans to improve the observations of < 5 GeV neutrinos in IceCube, with which we plan to probe more transient events in the future. These improvements include the addition of direction reconstruction at these energies, and optimization of the noise rejection. With these improvements, GRB 221009A is just the start of the low-energy neutrino search from transient events with IceCube.