Speaker
Description
High-energy neutrinos directly probe hadronic interactions, yet the sources of most of IceCube’s diffuse astrophysical neutrino flux remain unknown. The lack of significant point-source detections suggests that much of this flux may arise from populations of faint sources, motivating population-level searches. IceCube’s high-energy neutrino alert program enables a data-driven search for additional emission from the directions of astrophysical neutrino candidates without relying on predefined source catalogs. The forthcoming IceCat-2 catalog features substantially improved alert localizations, reducing background contamination and enhancing search sensitivity. Building on the IceCat-1 analysis, we search for additional neutrino emission associated with IceCat-2 alerts at both the individual-alert and population levels across four timescales. I will present the results and constraints on the maximum contribution of the underlying source populations to the diffuse astrophysical neutrino flux.