10:00 AM - 10:15 AM
[PEM26-05] Dynamical Petschek Reconnection: New Mechanism of Fast Magnetic Reconnection
Keywords:Magnetic reconnection, Solar flare
We perform resistive MHD simulation in a large system with a high spatial resolution and find slow mode MHD shocks, which are predicted by Petschek, spontaneously form even with the uniform resistivity. In this process, fast motion of large plasmoids in the current sheet play an important role and slow mode shocks form in front of moving plasmodia (fig1). This process exceeds magnetic reconnection intermittently and repeatedly because plasmoids are ejected and form repeatedly. This process enhances reconnection and achieve normalized reconnection rate of 0.01, which is necessary to explain the time scale of solar flares (fig2).
We name this fast reconnection regime 'Dynamical Petschek Reconnection'. In this regime, microscopic physics or anomalous resistivity is not necessary and only uniform resistivity is enough to realize fast reconnection. Motion of plasmoid affect the surrounding plasma flow and this flow play a role to localize electric current. As a consequence, slow mode MHD shocks, which are predicted by Petschek, form spontaneously and energy conversion occurs efficiently.