What determines the structure of short gamma-ray burst jets?

Understand

The discovery of GRB 170817A, the first unambiguous off-axis short gamma-ray burst arising from a neutron star merger, has challenged our understanding of the angular structure of relativistic jets.

• Studies of the jet propagation usually assume that the jet is ejected from the central engine with a top-hat structure and its final structure, which determines the observed light curve and spectra, is primarily regulated by the interaction with the nearby environment.
• However, jets are expected to be produced with a structure that is more complex than a simple top-hat, as shown by global accretion simulations.
• We present numerical simulations of short GRBs launched with a wide range of initial structures, durations and luminosities.