Density and Magnetic Field Evolution

Case A: Magnetized Irrotational

Here we look at the time evolution of the rest-mass density and magnetic fields. The rest-mass density is normalized to the maximum central density at $t/M = 230$. Time is measured in $M = 1.5 \times 10^{-2} (M_{NS} /1.625M_{\odot} ) \rm ms$. The neutron stars spiral inwards, forming a hypermassive neutron star (HMNS) and a disk of matter that orbits it. Eventually the HMNS undergoes delayed collapse, and a black hole is formed. We can see that the white magnetic field lines become collimated above and below the black hole, and that matter is ejected at mildly relativistic speeds. The field lines above the poles form a helical funnel which drives and confines the matter in the jet. The BH remnant has a spin of $a_{BH}/M_{BH} \approx 0.8$.

Fig. 1-1: Density and magnetic fields	Fig. 1-2: Density and magnetic fields	Fig. 1-3: Density and magnetic fields
Fig. 1-4: Density and magnetic fields	Fig. 1-5: Density and magnetic fields	Fig. 1-6: Density and magnetic fields