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

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.