Figure 18: Snapshots of the logarithm of the density (normalized to the density of the ambient medium) for a cold baryonic (top panel), a cold leptonic (central panel) and a hot leptonic (bottom panel) relativistic jet at t  6.3 × 10⁶ y, respectively (from Scheck et al. [256]). The black lines are iso-contours of the beam mass fraction with X = 0.1 (outermost) and X = 0.9 (innermost). These values correspond to the boundaries of the cocoon and the beam, respectively. The time evolution of the hot leptonic model is shown in the movie in Figure 19.