Figure 8

Figure 8: Lagrangian radii around each of the two SBH particles in an equal-mass merger simulation [150]. From bottom to top, the radii enclose $-4 10$ , $-3.5 10$ , $-3 10$ , $- 2.5 10$ , $-2 10$ , $-1.5 10$ and $10- 1$ in units of the mass of one galaxy before the merger. The binary becomes “hard” at $t ~~ 11$ , and very rapidly heats the surrounding stellar fluid, lowering the local density.