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.