Multi-Messenger Search for Neutrino and Gravitational-Wave Emissions from Binary Black Holes Near Active Galactic Nuclei
Leonardo Ricca, Matthias Vereecken, Christoph Raab, Mathieu Lamoureux, Giacomo Bruno, Gwenhaël De Wasseige
TL;DR
This work tackles the problem of detecting joint gravitational-wave and neutrino emission from binary black holes embedded in Active Galactic Nuclei (AGNs), a scenario in which AGN environments may enable multimessenger signals. It introduces a Bayesian framework that links subthreshold LVK GW triggers, IceCube neutrino candidates, and Quaia AGN catalogs, leveraging spatial coincidence with known AGNs to suppress background and allow inclusion of weaker GW signals. The method combines BAYESTAR GW localization, fast Bayesian neutrino inference, and an AGN-informed prior to compute a ranking statistic that enhances the significance of true associations. A sensitivity study using a GW190521-inspired injection demonstrates the framework’s potential to detect or constrain neutrino emission from BBH mergers in AGNs, marking a step toward robust multimessenger probes of BBH formation and AGN physics.
Abstract
Binary black holes (BBHs) in the vicinity of Active Galactic Nuclei (AGNs) are particularly interesting systems from both a cosmological and astrophysical point of view. Matter and radiation fields within the dense AGN environment could produce electromagnetic and neutrino emission in addition to gravitational waves (GWs). Moreover, interactions between BBHs and AGN accretion disks are expected to influence BBH formation channels and merger rates. Understanding these sources could help explain the unexpectedly high BBH masses observed through GWs by the LIGO-Virgo-KAGRA collaborations. We present a search for coincident gravitational-wave and neutrino emission from AGNs. Our innovative approach combines information from gravitational-wave data, neutrino observations, and AGN optical catalogs to increase the chances of identifying potential sources and studying their properties. We assess the sensitivity of the search using subthreshold gravitational-wave candidates from LIGO-Virgo-KAGRA data, neutrino event candidates from public IceCube Neutrino Observatory data and AGN candidates from the Quaia catalog. A confident detection of such an event would mark a breakthrough in multi-messenger astronomy.