Gamma-Ray Burst Prompt Emission from Relativistic Plasma Turbulence

Black hole-driven relativistic astrophysical jets are believed to power the bright electromagnetic radiation observed in gamma-ray bursts (GRBs). The prompt emission of GRBs is generally attributed to an energy dissipation and particle acceleration mechanism operating in situ within the jet at large distances from the black hole. However, despite decades of research, the precise physical mechanism responsible for the GRB prompt emission has remained elusive. Utilizing first-principles Particle-in-Cell (PIC) simulations of relativistic plasma turbulence, we have established a novel physics-based model for the prompt emission generated by relativistic magnetized turbulence within the jet. We will show that particle acceleration and strong radiative cooling in a relativistic turbulent plasma is characterized by a nonthermal particle spectrum that develops rapidly within a few eddy turnover times. The energy transferred from the magnetic field to the particles is then radiated away on extremely short timescales, even shorter than the light crossing time of the system. We will show that the turbulent-acceleration model successfully reproduces the observed spectral energy distributions and light curve variability of the analyzed GRBs. We will compare and contrast the turbulent-acceleration model with previous alternative models, such as the internal shock model and the magnetic reconnection model. Finally, we will discuss the observational constraints that could pin down which mechanism is the driver of the prompt emission.