标题： 吸积中子星磁层中半相对论喷流的形成：热气泡注入磁塔 显示英文标题

标题： Formation of Semi-relativisitc Jets from Magnetospheres of Accreting Neutron Stars: Injection of Hot Bubbles into a Magnetic Tower

摘要： 我们展示了弱磁化中子星与其吸积盘之间磁相互作用的二维半电阻磁流体力学（MHD）模拟结果。广义相对论效应通过使用伪牛顿势来模拟。我们发现，沿盘旋转轴方向良好集束的喷流是由以下机制形成的：(1) 连接中子星和盘的磁环由于中子星与盘之间的差速自转而扭曲。(2) 盘注入的扭折引发磁环的膨胀。(3) 膨胀的磁环在其中加速的盘物质以集束双极喷流的形式形成磁塔。喷流工作表面的传播速度约为光速的10% ($\sim 0.1c$)。(4) 在膨胀磁环内部发生的磁重联间歇性地向磁塔注入热气泡。气泡的喷射速度在我们的模拟中约为发射点处的局地阿尔芬速度和$\sim 0.2c$。(5) 在塔内移动的热气泡赶上喷流的工作表面。由磁重联产生的高能电子是射电辐射的可能来源。我们的模型可以解释来自弱磁化 ($|{\boldmath$B_{*}$}|\le 10^{9}$ 高斯) 中子星的窄喷流的形成过程，并且可以解释在天蝎座 X-1 中观测到的核心和瓣的射电暴之间的相关性。 显示英文摘要

摘要： We present the results of 2.5-dimensional resistive magnetohydrodynamic (MHD) simulations of the magnetic interaction between a weakly magnetized neutron star and its accretion disk. General relativistic effects are simulated by using the pseudo-Newtonian potential. We find that well-collimated jets traveling along the rotation axis of the disk are formed by the following mechanism: (1) The magnetic loops connecting the neutron star and the disk are twisted due to the differential rotation between the neutron star and the disk. (2) Twist injection from the disk initiates expansion of the loop. (3) The expanding magnetic loops create a magnetic tower in which accelerated disk material travel as collimated bipolar jets. The propagation speed of the working surface of the jet is the order of 10% of the speed of light ($\sim 0.1c$). (4) Magnetic reconnection taking place inside the expanding magnetic loops injects hot bubbles intermittently into the magnetic tower. The ejection speed of the bubble is the order of the local Alfv\'{e}n speed of the launching point and $\sim 0.2c$ in our simulations. (5) The hot bubbles moving inside the tower catch up with the working surface of the jet. High energy electrons created by the magnetic reconnection are a plausible source of radio emission. Our model can explain the formation process of a narrow jet from a weakly magnetized ($|{\boldmath$B_{*}$}|\le 10^{9}$ gauss) neutron star and the correlation between radio flares of the core and of the lobe observed in Sco X-1.