Speaker
Description
Multimessenger astronomy has become a key approach in modern astrophysics by combining signals from different messengers, such as gravitational waves (GWs), neutrinos, and electromagnetic radiation, to explore the universe’s most energetic events. This study presents a triggered coherent search for GWs using High-Energy Neutrinos (HENs) detected by the ANTARES and KM3NeT telescopes during the third LIGO–Virgo–KAGRA observational run (O3). Neutrinos, due to their weak interaction with matter, travel largely undisturbed from their sources, providing precise timing and directional information. A Joint search between GWs and neutrinos can therefore enhance the sensitivity for GW searches and help constrain the physical mechanisms that power extreme astrophysical phenomena, such as relativistic jets, gamma-ray bursts, and kilonovae. Coherent GW analyses, though powerful, are computationally costly when scanning wide sky regions. To address this, we employ X-pipeline, a software package for unmodeled GW searches that combines detector data to identify coherent power excesses. By exploiting temporal and spatial constraints from neutrino triggers, our method achieves an improvement in sensitivity relative to all-sky searches. We focus on evaluating the background around neutrino detection times, testing X-pipeline’s ability to recover simulated signals, and setting upper limits on GW emission for the analyzed neutrino events.
