Constraints on populations of neutrino sources from searches in the directions of IceCube neutrino alerts

Abstract

Beginning in 2016, the IceCube Neutrino Observatory has sent out alerts in real time containing the information of high-energy ($E\gtrsim 100$~TeV) neutrino candidate events with moderate-to-high ($\gtrsim 30$\%) probability of astrophysical origin. In this work, we use a recent catalog of such alert events, which, in addition to events announced in real-time, includes events that were identified retroactively, and covers the time period of 2011-2020. We also search for additional, lower-energy, neutrinos from the arrival directions of these IceCube alerts. We show how performing such an analysis can constrain the contribution of rare populations of cosmic neutrino sources to the diffuse astrophysical neutrino flux. After searching for neutrino emission coincident with these alert events on various timescales, we find no significant evidence of either minute-scale or day-scale transient neutrino emission or of steady neutrino emission in the direction of these alert events. This study also shows how numerous a population of neutrino sources has to be to account for the complete astrophysical neutrino flux. Assuming sources have the same luminosity, an $E^{-2.5}$ neutrino spectrum and number densities that follow star-formation rates, the population of sources has to be more numerous than $7\times 10^{-9}{\text{Mpc}}^{-3}$. This number changes to $3\times 10^{-7}{\text{Mpc}}^{-3}$ if number densities instead have no cosmic evolution.

22 pages, 9 figures 2 Tables

References in corpus (14)

• Cosmic Star Formation History
• All-sky search for time-integrated neutrino emission from astrophysical sources with 7 years of IceCube data
• The contribution of Fermi-2LAC blazars to the diffuse TeV-PeV neutrino flux
• A tidal disruption event coincident with a high-energy neutrino
• Improved Characterization of the Astrophysical Muon-Neutrino Flux with 9.5 Years of IceCube Data
• Methods for point source analysis in high energy neutrino telescopes
• Observational evidence for the origin of high-energy neutrinos in parsec-scale nuclei of radio-bright active galaxies
• Searches for Neutrinos from Gamma-Ray Bursts using the IceCube Neutrino Observatory
• IceCube Search for Neutrinos Coincident with Compact Binary Mergers from LIGO-Virgo's First Gravitational-Wave Transient Catalog
• Cosmic neutrinos from temporarily gamma-suppressed blazars
• Follow-up of astrophysical transients in real time with the IceCube Neutrino Observatory
• Search for Spatial Correlations of Neutrinos with Ultra-High-Energy Cosmic Rays
• Search for High-Energy Neutrinos from Ultra-Luminous Infrared Galaxies with IceCube
• Neutrino Counterparts of Fast Radio Bursts

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• IceCat-1: the IceCube Event Catalog of Alert Tracks
• Characterization of the Astrophysical Diffuse Neutrino Flux using Starting Track Events in IceCube
• Searches for neutrinos in the direction of radio-bright blazars with the ANTARES telescope
• Neutrino flares of radio blazars observed from TeV to PeV
• Search for Continuous and Transient Neutrino Emission Associated with IceCube's Highest-Energy Tracks: An 11-Year Analysis
• Hard X-ray emission from blazars associated with high-energy neutrinos
• Beyond first light: Global monitoring for high-energy neutrino astronomy
• On the 'Loose' Constraint from IceCube Neutrino Non-Detection of GRB 230307A
• Deciphering the Sources of Cosmic Neutrinos
• Flat Spectrum Radio Quasars as high-energy neutrino sources
• Constraints on the origins of the Galactic neutrino flux