Figure 4

Dynamical Friction on a Single Particle (N-body)—The inspiral of a single massive BH in a Plummer sphere due to dynamical friction, as computed by integrating equation (13) (in dashed-orange) and by direct N-body (in blue, using the Kira integrator). The N-body results are averaged over 50 independent realizations, with the solid blue line and the blue shaded region indicating the median and 90-percentile values of the radius when binned every 1 dynamical time. We consider BHs with masses 10 and 20 times the mass of the stars (top and bottom, respectively)