Revisiting the Light Curves of Gamma-ray Bursts in the Relativistic Turbulence Model

TL;DR

This paper investigates the variability in gamma-ray burst light curves within the relativistic turbulence model, considering both eddies and inter-eddy medium contributions to explain observed lead/lag phenomena.

Contribution

It introduces a combined model of eddies and inter-eddy medium to better understand gamma-ray emission timing in GRBs, challenging previous interpretations.

Findings

Gamma-ray emission can lead or lag synchrotron emission.

Observed lead/lag may not reflect intrinsic emission component delays.

Model explains gamma-ray lead in GRB 080319B.

Abstract

Rapid temporal variability has been widely observed in the light curves of gamma-ray bursts (GRBs). One possible mechanism for such variability is related to the relativistic eddies in the jet. In this paper, we include the contribution of the inter-eddy medium together with the eddies to the gamma-ray emission. We show that the gamma-ray emission can either lead or lag behind the observed synchrotron emission, where the latter originates in the inter-eddy medium and provides most of seed photons for producing gamma-ray emission through the inverse-Compton scattering. As a consequence, we argue that the lead/lag found in non-stationary short-lived light curves may not reveal the intrinsic lead/lag of different emission components. In addition, our results may explain the lead of gamma-ray emission with respect to optical emission observed in GRB 080319B.