Figure 9

Figure 9: This figure shows the apparent horizons (actually MOTSs) for a spherically symmetric numerical evolution of a black hole accreting a narrow shell of scalar field, the 800.pqw1 evolution of Thornburg [155]. Part (a) of this figure shows Θ (r ) (here labelled H) for a set of equally-spaced times between t=19 and t=20, while Part (b) shows the corresponding MOTS radius h (t) and the Misner–Sharp [111], [112, Box 23.1] mass m (h) internal to each MOTS. Notice how two new MOTSs appear when the local minimum in Θ(r) touches the Θ=0 line, and two existing MOTS disappear when the local maximum in Θ(r) touches the Θ=0 line.