Tether-cutting and Overlying Magnetic Reconnections in an MHD Simulation of Prominence-cavity System

We investigate the magnetic reconnection in an MHD simulation of a coronal flux rope (MFR) confined by helmet streamer, where prominence-cavity system forms. This includes hot cavity surrounding prominence with horns and central core above prominence. The evolution from quasi-equilibrium to eruption can be divided into four phases: quasi-static, slow rise, fast propagation phases. emerged MFR initially stays quasi-static occurs at overlying high-Q (squashing factor) apex region, which gradually evolves hyperbolic tube (HFT). decrease integrated tension force (above location reconnection) is due removal confinement enhanced between fields HFT, thus engines rise nearly constant velocity. Once reaches regime torus instability, another HFT immediately forms dip region under MFR, followed explosive flare reconnection. resultant exponentially increases, drives exponential MFR. enters phase, once its height about one solar radius photosphere. reproduces main processes group eruptions especially those occurring on quiet Sun.