Magnetic Cannonball Model for Gamma-Ray Bursts

摘要

We propose a new magnetic-driven mechanism for gamma-ray bursts. The collapse of a magnetosphere onto a black hole can generate a strong outward Poynting flux that drives a baryon-free fireball called the magnetic cannonball. The relativistic outflow of the cannonball interacts with interstellar matter and forms a shock with the help of its magnetic field. The magnetic field of 10~4 G at the shock can induce synchrotron radiation with peaks observed at 10~2 keV. This magnetic field in the cannonball can also confine high-energy protons (γ_0 > 30), which are required for delayed high-energy photons (>25 GeV), which were observed following a burst on 1994 February 17.