On the origin of extended nonthermal optical emission in extragalactic

The extended nonthermal optical emission of extragalactic jets can only be explained by some in situ reacceleration. Since the jets are magnetized plasma flows, the dissipation of the magnetic field via magnetic reconnection seems to be a promising candidate for the reacceleration mechanism. Reconnection converts magnetic energy, which is to be regarded as the only energy supply in the entire jet region, into particle energy via continuous acceleration. We show that inertia-driven reconnection operating in a highly filamentary magnetic flux rope topology can provide a satisfying solution to the reacceleration problem for the collisionless magnetized jet plasma.