Archival search for sub-TeV neutrino counterparts to sub-threshold Gravitational Wave events with IceCube

The IceCube Neutrino Observatory actively participates in multi-messenger follow-ups of gravitational wave (GW) events. With the release of the Gravitational Wave Transient Catalogue (GWTC)-2.1 and -3, sub-threshold GW event information from the third observation run of the LIGO-Virgo-KAGRA (LVK) collaboration is publicly available. This offers an opportunity to search for their corresponding neutrino counterparts. For these sub-threshold GWs, identified via template-based and minimally-modelled search pipelines, archival searches for neutrinos can enhance their astrophysical significance, and improve localization.

In this contribution, we perform a catalogue-based search for sub-TeV neutrino counterparts to some shortlisted sub-threshold GWs. This study uses archival data from IceCube's dense-infill array, DeepCore. By correlating IceCube data with sub-threshold GWs, we aim to contribute to the ongoing efforts to identify common astrophysical sources of neutrino and GW. We present the current status of this search and its role in advancing multi-messenger astronomy, paving the way for deeper exploration of transient astrophysical events.