3-DIMENSIONAL STEADY-STATE MAGNETIC RECONNECTION

A family of three-dimensional models of reconnection is presented in w hich the different members of the family are characterized by the vort icity with which plasma flows towards the reconnection site. The natur e of this inflow also determines the size and speed of the outflow jet that carries reconnected field lines away from the reconnection site, and the shape of the MHD shocks that bound it. Flows with positive vo rticity are of a flux pile-up type, for which the outflow jet is faste st and narrowest. Among those with negative vorticity is the three-dim ensional analogue of Petschek reconnection. Not all combinations of vo rticity and reconnection rate are possible; for those solutions with n egative vorticity, there is a maximum reconnection rate. As the magnet ic Reynolds number R(me), or the current density is increased, this ma ximum is reduced and the possible types of solution become more polari zed towards the two extremes of flux pile-up and slow compression regi mes. Given a distribution of vorticities and inflow speeds, these mode ls give the corresponding distribution of possible steady-state reconn ection rates. As an illustrative example, we take Gaussian distributio ns of both to show that the resulting distribution is dominated by the flux pile-up regime.