Studies of systematic uncertainty effects on IceCube's real-time angular uncertainty

TL;DR

This paper investigates how systematic uncertainties, especially related to ice models, affect the accuracy of IceCube's real-time neutrino source localization, using novel simulation tools to improve error estimates.

Contribution

It introduces a new simulation approach that accounts for multiple systematic uncertainties in IceCube's real-time neutrino localization.

Findings

Systematic uncertainties significantly impact localization accuracy.

A novel simulation tool effectively models multiple nuisance parameters.

Results enable more robust real-time error estimates.

Abstract

Sources of astrophysical neutrinos can potentially be discovered through the detection of neutrinos in coincidence with electromagnetic or gravitational waves. Real-time alerts generated by IceCube play an important role in this search, acting as triggers for follow-up observations with instruments sensitive to other wavelengths. Once a high-energy event is detected by the IceCube real-time program, a complex and time consuming direction reconstruction method is run in order to calculate an accurate localisation. To investigate the effect of systematic uncertainties on the uncertainty estimate of the location, we simulate a set of high-energy events with a wide range of directions for different ice model realisations, the dominant systematic error in our localization uncertainty. This makes use of a novel simulation tool, which allows the treatment of systematic uncertainties with multiple continuously varied nuisance parameters. These events will be reconstructed using various reconstruction methods. This study will enable us to include systematic uncertainties in a robust manner in the real-time direction and error estimates.