Gamma-Ray Burst without Baryonic and Magnetic Load?

Abstract

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 ($e^{\pm }$) 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.

10 pages, 3 figures, final version to be published in Progress of Theoretical Physics

References in corpus (3)

• Stability of Relativistic Jets from Rotating, Accreting Black Holes via Fully Three-Dimensional Magnetohydrodynamic Simulations
• Magnetic acceleration of ultra-relativistic jets in gamma-ray burst sources
• High-Energy Aspects of Astrophysical Jets

Cited by in corpus (8)

• The Physics of Gamma-Ray Bursts and Relativistic Jets
• TeV-PeV Neutrinos from Low-Power Gamma-Ray Burst Jets inside Stars
• The peak energy of dissipative GRB photospheres
• Gamma-Ray Burst Science in the Era of the Cherenkov Telescope Array
• Population III Gamma-Ray Bursts and Breakout Criteria for Accretion-Powered Jets
• Prospects for Detecting Gamma-Ray Bursts at Very High Energies with the Cherenkov Telescope Array
• Inverse Compton cooling in Klein-Nishina regime and GRB prompt spectrum
• Scattered Short Gamma-Ray Bursts as Electromagnetic Counterparts to Gravitational Waves and Implications of GW170817 and GRB 170817A