with a spatial extent of $\sim 35.4\,{{\rm km}}$), where the first evidence was given that the merger of a binary system of magnetized neutron stars can lead to the formation of a magnetic-jet structure. Hence, although in a resistive framework, the simulations reported here can be considered as a “higher-resolution” counterpart of those presented in Ref. [@Rezzolla:2011]. We also note that when considering initial data consisting of a binary in quasicircular orbits (see Sec. \[sec:bns:lifetime\]) we do not activate the extra refinement level after the merger, hence keeping a resolution of $\Delta
x\approx 296~{{\rm m}}$ to describe the HMNS. We do this so as to have two different resolutions to describe the HMNS and hence to study the numerical consistency of the solution.

To reduce the computational cost associated with the numerical evolution of an equal-mass binary, we use a reflection-symmetry condition across the $z=0$ plane and a $\pi$-symmetry condition across the $x=0$ plane. These conditions respect the symmetries of the scenario we are investigating. The outer boundary conditions are set by using simple zeroth-order extrapolation of the hydrodynamic variables. For the electromagnetic and spacetime variables, we employ simple Sommerfeld radiative boundary conditions because of the nature of the fields. 