Signatures of collisionless magnetic reconnection

[1] Simulations of magnetic reconnection in simple systems without a guide field predict the formation of a spatially antisymmetric out-of-plane magnetic field signature and a symmetric perturbation in the plasma pressure. Here we show, using two fluid simulations and analytic arguments, that these signatures are not in fact a generic feature of fast reconnection. Rather, in the strong guide field limit the pressure perturbation becomes antisymmetric, while the perturbation in the out-of-plane field can be either symmetric for beta(x) similar to 1 or antisymmetric for beta(x) >> 1, where beta(x) is the plasma beta defined using the reconnection magnetic field just upstream of the reconnection region.