Gamma-ray Burst Prompt Emission: Jitter Radiation in Stochastic Magnetic Field Revisited

TL;DR

This paper revisits jitter radiation as a mechanism for gamma-ray burst prompt emission, linking it to turbulent magnetic fields and particle acceleration, and suggests GRBs as sources of high-energy cosmic rays.

Contribution

It demonstrates that jitter radiation can explain GRB prompt emission considering turbulent magnetic fields and estimates maximum electron energies reaching 10^{14} eV.

Findings

Jitter radiation can account for GRB prompt emission under certain conditions.

Turbulence spectrum influences the spectral properties of GRB emission.

Relativistic electrons can reach energies up to 10^{14} eV, making GRBs potential sources of high-energy cosmic rays.

Abstract

We revisit the radiation mechanism of relativistic electrons in the stochastic magnetic field and apply it to the high-energy emissions of gamma-ray bursts (GRBs). We confirm that jitter radiation is a possible explanation for GRB prompt emission in the condition of a large electron deflection angle. In the turbulent scenario, the radiative spectral property of GRB prompt emission is decided by the kinetic energy spectrum of turbulence. The intensity of the random and small-scale magnetic field is determined by the viscous scale of the turbulent eddy. The microphysical parameters $\epsilon_e$ and $\epsilon_B$ can be obtained. The acceleration and cooling timescales are estimated as well. Due to particle acceleration in magnetized filamentary turbulence, the maximum energy released from the relativistic electrons can reach a value of about $10^{14}$ eV. The GeV GRBs are possible sources of high-energy cosmic-ray.