Simulation of Relativistic Jet Flow in Long Gamma-Ray Bursts: Effect of Energy Injection Rate

Abstract

Simulation of Relativistic Jet Flow in Long Gamma-Ray Bursts: Effect of Energy Injection Rate

Seonho Kim1, Jeongbhin Seo2, Kyujin Kwak1, Dongsu Ryu1 1 Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea, 2Los Alamos National Laboratory, USA

Gamma-ray bursts (GRBs) are known to release a huge amount of energy during a short period of time in the format of the ultra-relativistic flow. So far, various scenarios have been proposed to explain the environment of the central engine that launches the GRB jet. We simulate three-dimensional ultra-relativistic long GRB jets with different energy injection rates by using our new relativistic hydrodynamics code. Our simulation traces the jet evolution from inside the stellar envelope to the expansion into the ambient medium after breakout. We analyze the morphology, structure, and kinematic characteristics of the GRB jet and investigate the effect of the energy injection rate on these physical quantities. We also study shock, shear, and turbulence to evaluate the structure formation of the GRB jets. Our current study provides a hint for the particle acceleration mechanism within the GRB jet.