Figure 2

Figure 2: This figure shows part of a simulation of the spherically symmetric collapse of a model stellar core (a 5 Γ = 3 polytrope) to a black hole. The event horizon (shown by the dashed line) was computed using the “integrate null geodesics forwards” algorithm described in Section 5.1; solid lines show outgoing null geodesics. The apparent horizon (the boundary of the trapped region, shown shaded) was computed using the zero-finding algorithm discussed in Section 8.1. The dotted lines show the world lines of Lagrangian matter tracers and are labeled by the fraction of baryons interior to them. Figure reprinted with permission from [142]. © 1980 by the American Astronomical Society.