2011/03/31 by Kunihito Ioka, K. Ioka, Y. Ohira +5 · 10 citations
Earth and Planetary Sciences · Physics and Astronomy · #Acceleration #Afterglow #Astrophysics and Cosmic Phenomena #Baryon #Cosmic ray #Earth Systems and Cosmic Evolution #Gamma-ray burst #Gamma-ray bursts and supernovae #Jet (fluid) #Lorentz factor #Photon #Photosphere #astro-ph.HE
paper · pdf · doi:10.1143/ptp.126.555
published in Progress of Theoretical Physics 126(3), 555-564 (Oxford University Press) · 10 pages, 3 figures, final version to be published in Progress of Theoretical Physics
openalex publication_date 2011/09/01 · arxiv created 2011/09/14 · arxiv updated 2015/04/23 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We show that, contrary to common belief, internal shocks can arise in an accelerating radiation-dominated jet if it is confined even weakly to a converging opening angle because the acceleration declines. The radiation-dominated internal shock (RDIS) enables a very efficient yet highly nonthermal emission by Fermi-like photon acceleration, keeping the electron-positron ( e± ) pair photosphere and inertia up to a high Lorentz factor > 1000. In gamma-ray bursts (GRBs), a weak confinement would persist beyond the progenitor star or surrounding matter because of the fast cocoon accompanying the breakout jet. The simplest model predicts few high-energy cosmic rays and neutrinos, and a correlation between the early afterglow and the GeV-TeV prompt emission. The central engine allows a less fine-tuned baryon load than previously thought, even including pure-leptonic unmagnetized outflows.