Beam instabilities in the outer magnetosphere. Left: parallel momentum (p ∣∣) distributions of e ± (gray) and gamma rays (black) in regions (a) and (b) in the right panel. For gamma rays, we show distributions of p ∣∣/2 (their momentum is split between the created e + and e −). (a) Gamma rays from the current sheet (black peak) inject e ± (gray peak). (b) Gamma rays from the separatrix (thin black peak) and current sheet (wider black peak) inject different e ± beams. Right: charge density ρ (color bar) and charge bunches.