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Bibliographic Details
Main Authors: Li, An, Gao, He, Lan, Lin, Zhang, Bing
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2408.01161
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Table of Contents:
  • The composition of gamma-ray burst (GRB) jets remained a mystery until recently. In practice, we usually characterize the magnetization of the GRB jets ($σ_0$) through the ratio between the Poynting flux and matter (baryonic) flux. With the increasing value of $σ_0$, magnetic energy gradually takes on a dominant role in the acceleration and energy dissipation of the jet, causing the proportion of thermal component in the prompt-emission spectrum of GRBs to gradually decrease or even be completely suppressed. In this work, we conducted an extensive analysis of the time-resolved spectrum for all \textit{Fermi} GRBs with known redshift, and we diagnose $σ_0$ for each time bin by contrasting the thermal and nonthermal radiation components. Our results suggest that most GRB jets should contain a significant magnetic energy component, likely with magnetization factors $σ_{0}\geq 10$. The value of $σ_{0}$ seems vary significantly within the same GRB. Future studies with more samples, especially those with lower-energy spectral information coverage, will further verify our results.