# Density and Magnetic Field Evolution

## Density and Magnetic Field Evolution

Here we look at the time evolution of the rest-mass density and magnetic fields. The rest-mass density is normalized to the maximum density at t = 0. Time is measured in $M = 2.5 \times 10^{-2} ms$. The neutron star spirals in towards the black hole until it is tidally disrupted, and then it forms a disk of matter that orbits the black hole. We can see that the 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 wall which drives and confines the matter in the jet. The luminosity of the source is $\sim 10^{51} ergs/s$ and the lifetime of the jet is $\sim 0.5 s$, values that are consistent with observations of sGRBs. The opening angle of the jet is 20 degrees.

 Fig. 1-1: Density and Magnetic Fields at time t/M = 649 Fig. 1-2: Density and Magnetic Fields at time t/M = 868 Fig. 1-3: Density and Magnetic Fields at time t/M = 3699 Fig. 1-4: Density and Magnetic Fields at time t/M = 5862
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## Starry Night

Here we look at the same time evolution of the density and magnetic fields, except now we portray it on a dark starry background, which highlights the density evolution.

 Fig. 1-1: Density and Magnetic Fields at time t/M = 649 Fig. 1-2: Density and Magnetic Fields at time t/M = 868 Fig. 1-3: Density and Magnetic fields at time t/M = 3699 Fig. 1-4: Density and Magnetic Fields at time t/M = 5862
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