Subphotospheric Neutrinos from Gamma-Ray Bursts: The Role of Neutrons

TL;DR

This paper explores how neutrons in gamma-ray burst outflows can produce subphotospheric gamma rays and neutrinos, offering insights into burst mechanisms and jet composition through neutrino detection.

Contribution

It introduces a model linking neutron-induced inelastic collisions to gamma-ray and neutrino production in gamma-ray bursts, emphasizing the importance of neutrino searches.

Findings

Neutron interactions can produce detectable subphotospheric gamma rays.

Neutrino signals in the 10-100 GeV range are predicted from GRBs.

Detection of these neutrinos can discriminate emission mechanisms and jet composition.

Abstract

Relativistic outflows with neutrons inevitably lead to inelastic collisions, and resulting subphotospheric gamma rays may explain prompt emission of gamma-ray bursts. In this model, hadronuclear, quasithermal neutrinos in the 10-100 GeV range should be generated, and they may even have a high-energy tail by neutron-proton-converter or shock acceleration mechanisms. We demonstrate the importance of dedicated searches with DeepCore+IceCube, though such analyses have not been performed. Successful detections enable us to discriminate among prompt emission mechanisms, probe the jet composition, and see roles of relativistic neutrons as well as effects of cosmic-ray acceleration.