Searching for sub-TeV IceCube neutrinos correlated to sub-threshold GW events

TL;DR

This paper discusses an archival search for neutrino counterparts to sub-threshold gravitational wave candidates using IceCube data, aiming to enhance multi-messenger astrophysics and source localization.

Contribution

It introduces a method for searching archival IceCube neutrino data for correlations with sub-threshold GW candidates, advancing multi-messenger detection efforts.

Findings

No significant neutrino-GW correlations found yet.

The search improves understanding of GW parameter thresholds.

Method sets groundwork for future multi-messenger discoveries.

Abstract

The IceCube Neutrino Observatory is active in multi-messenger follow-ups of Gravitational Wave (GW) events. Since the release of the Gravitational Wave Transient Catalogue (GWTC)-2.1 by the LIGO-Virgo-KAGRA (LVK) collaboration, sub-threshold GW candidates have been made publicly available. However, they were not followed up in real-time to search for neutrino counterparts. For a deeper understanding of these sub-threshold candidates, archival searches are essential. Finding evidence for a neutrino counterpart will enhance the astrophysical significance of these sub-threshold GW candidates and improve their localisation. Additionally, it will aid in better understanding possible thresholds on specific GW parameters, beyond which the sub-threshold GW candidates could also be promising multi-messenger sources. Thus, the search contributes to the ongoing efforts to establish correlations between astrophysical neutrinos and GW sources. Here, we present the current status of this ongoing work with the IceCube neutrino data.