Neutrino Production Associated with Late Bumps in Gamma-Ray Bursts and Potential Contribution to Diffuse Flux at IceCube

TL;DR

This paper explores the potential link between late-time gamma-ray burst bumps and the production of high-energy neutrinos, suggesting that such sources could contribute to IceCube's diffuse neutrino flux.

Contribution

It introduces a model-independent analysis of delayed neutrino production from GRBs and estimates their contribution to IceCube's observed neutrino flux.

Findings

Up to 10% of IceCube events may be linked to late GRB activities.

Late GRB neutrino sources are likely nonrelativistic or mildly relativistic.

Such sources could account for a few of IceCube's diffuse neutrino events.

Abstract

IceCube has detected many TeV--PeV neutrinos, but their astrophysical origins remain largely unknown. Motivated by the observed late-time X-ray/optical bumps in some gamma-ray bursts (GRBs), we examine the correlation between IceCube neutrinos and GRBs allowing delayed neutrinos $\sim$days after the prompt gamma rays. Although we have not found any definitive correlation, up to $\sim$10\% of the events observed so far at IceCube may have been neutrinos produced by the late-time GRB activities at $\sim$1 day. Assuming a connection between some IceCube events and the late GRB bumps, we show in a model-independent way that GRB sites capable of producing late $\sim$PeV neutrinos should be nonrelativistic or mildly relativistic. We estimate the diffuse neutrino flux from such sources and find that they can possibly account for a few IceCube events. Future observations of high-energy neutrinos and late-time GRB afterglows can further test the above proposed connection.