2005/11/23 by C. B. Hededal, Christian Busk Hededal, Åke Nordlund +2
Physics and Astronomy · #Astro and Planetary Science #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Gamma-ray bursts and supernovae #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0511662
5 pages, 4 figures, submitted to the Astrophysical Journal Letters
arxiv created 2005/11/23 · openalex publication_date 2005/11/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The radiation from afterglows of gamma-ray bursts is generated in the collisionless plasma shock interface between a relativistic outflow and a quiescent circum-burst medium. The two main ingredients responsible for the radiation are high-energy, non-thermal electrons and a strong magnetic field. In this Letter we present, for the first time, synthetic spectra extracted directly from first principles particle-in-cell simulations of relativist collisionless plasma shocks. The spectra are generated by a numerical Fourier transformation of the electrical far-field from each of a large number of particles, sampled directly from the particle-in-cell simulations. Both the electromagnetic field and the non-thermal particle acceleration are self-consistent products of the Weibel two-stream instability. We find that the radiation spectrum from a Γ=15 shock simulation show great resemblance with observed GRB spectra -- we compare specifically with that of GRB000301C.