Search for neutrino sources from the direction of IceCube alert events

We search for additional neutrino emission from the direction of IceCube’s highest energy public alert events. We take the arrival direction of 122 events with a high probability of being of astrophysical origin and look for steady and transient emission. We investigate 11 years of reprocessed and recalibrated archival IceCube data. For the steady scenario, we investigate if the potential emission is dominated by a single strong source or by many weaker sources. In contrast, for the transient emission we only search for single sources. In both cases, we find no significant additional neutrino component. Not having observed any significant excess, we constrain the maximal neutrino flux coming from all 122 origin directions (including the high-energy events) to Φ_{90%, 100 TeV} = 1.2 × 10⁻¹⁵ (TeV cm² s)⁻¹ at 100 TeV, assuming an E⁻² emission, with 90% confidence. The most significant transient emission of all 122 investigated regions of interest is the neutrino flare associated with the blazar TXS 0506+056. With the recalibrated data, the flare properties of this work agree with previous results. We fit a Gaussian time profile centered at μ_T = 57001⁺₋³⁸₂₆ MJD and with a width of σ_T = 64⁺₋³⁵₁₀ days. The best fit spectral index is γ = 2.3 ± 0.4 and we fit a single flavor fluence of J_{100 TeV} = 1.2⁺₋¹₀¹₈ × 10⁻⁸ (TeV cm²)⁻¹. The global p-value for transient emission is p_global = 0.156 and, therefore, compatible with background.