Recurrent solar jets in active regions
Recurrent solar jets in active regions
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DOI：
10.1051/0004-6361/200913752
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发表时间：
2010-03
影响因子：
6.5
通讯作者：
V. Archontis;K. Tsinganos;C. Gontikakis
中科院分区：
文献类型：
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作者：
V. Archontis;K. Tsinganos;C. Gontikakis
目标。我们研究了环形磁通管进入太阳大气层的情况及其与活动区域预先存在的场的相互作用。我们研究了碰撞磁场之间重复重新连接事件导致的喷流发射。方法。我们通过在高度分层的大气中求解随时间变化的电阻 MHD 方程来执行 3D 模拟。结果。通过环形磁通量管的出现构建了一个小的有源区域场。当新出现的通量与有源区域的环境场接触时，电流结构被建立并开始重新连接。当前结构周围的磁场拓扑在重新连接期间发生了巨大的改变。这种修改导致新的磁系统的形成，最终碰撞并重新连接。我们发现重联喷流在彼此垂直的方向上以连续的循环阶段发生，而在每个阶段它们都会将磁能和热等离子体释放到太阳大气中。在一系列喷流反复出现后，系统接近平衡，重新连接的效率大大降低。我们推断，新磁通量的出现会对活性区域场产生扰动，进而导致相邻磁场之间重新连接，并以喷射状发射的形式释放捕获的能量。这是首次在三维磁通量出现实验中证明了活动区域喷流的自洽重现。
Aims. We study the emergence of a toroidal flux tube into the solar atmosphere and its interaction with a pre-existing field of an active region. We investigate the emission of jets as a result of repeated reconnection events between colliding magnetic fields. Methods. We perform 3D simulations by solving the time-dependent, resistive MHD equations in a highly stratified atmosphere. Results. A small active region field is constructed by the emergence of a toroidal magnetic flux tube. A current structure is build up and reconnection sets in when new emerging flux comes into contact with the ambient field of the active region. The topology of the magnetic field around the current structure is drastically modified during reconnection. The modification results in a formation of new magnetic systems that eventually collide and reconnect. We find that reconnection jets are taking place in successive recurrent phases in directions perpendicular to each other, while in each phase they release magnetic energy and hot plasma into the solar atmosphere. After a series of recurrent appearance of jets, the system approaches an equilibrium where the efficiency of the reconnection is substantially reduced. We deduce that the emergence of new magnetic flux introduces a perturbation to the active region field, which in turn causes reconnection between neighboring magneticfields and the release of the trapped energy in the form of jet-likeemissions. This is the first time that self-consistent recurrency of jets in active regions is shown in a three-dimensional experiment of magnetic flux emergence.