High-energy Neutrinos from Outflows Powered by Kicked Remnants of Binary Black Hole Mergers in AGN Accretion Disks

Abstract

Merging of stellar-mass binary black holes (BBH) could take place within the accretion disk of active galactic nuclei (AGN). The resulting BH remnant is likely to accrete the disk gas at a super-Eddington rate, launching a fast, quasi-spherical outflow (wind). Particles will be accelerated by shocks driven by the wind, subsequently interacting with the shocked disk gas or radiation field through hadronic processes and resulting in the production of high-energy neutrinos and potential electromagnetic (EM) emissions. This study delves into the intricate evolution of the shock driven by the remnant BH wind within AGN disks. Subsequently, we calculated the production of neutrinos and the expected detection numbers for a single event, along with their contributions to the overall diffuse neutrino background. Our analysis, considering various scenarios, reveals considerable neutrino production and possible detection by IceCube for nearby events. The contribution of the remnant BH winds on the diffuse neutrino background is minor due to the low event rate density, but it can be improved to some extent for some optimistic parameters. We also propose that there could be two neutrino/EM bursts, one originating from the premerger BBH wind and the other from the remnant BH wind, with the latter typically having a time gap to the GW event of around tens of days. When combined with the anticipated gravitational waves (GW) emitted during the BBH merger, such a system emerges as a promising candidate for joint observations involving neutrinos, GWs, and EM signals.