论文标题
磁场对原始磁盘形成的影响
Influence of the magnetic field on the formation of protostellar disks
论文作者
论文摘要
我们以数值为单位的磁性旋转原恒星云的崩溃，质量为10 $ m_ {sun} $。模拟是在2D MHD Code Ellil的帮助下进行的。对于弱，中度和强的初始磁场的情况，研究了塌陷等温阶段的云的结构。仿真揭示了倒塌的原始云的通用分层结构，这些结构由内部的Qausi-Magnetostatc磁盘和其中心中的第一个核心组成。主要磁盘的大小随云的初始磁能而增加。当云的初始磁能超过其重力能量的20％以上时，磁制动将角动量从初级磁盘中有效地传输到包膜中。从第一核边界附近的区域发射的流出强度随着初始磁能的增加而增加。带有小电离分数的“死”区域，$ x <10^{ - 11} $，在第一个静水芯内和流出的底部内。欧姆耗散和双极扩散确定了该区域中原始磁盘进一步形成的条件。
We numerically model the collapse of magnetic rotating protostellar clouds with mass of 10 $M_{sun}$. The simulations are carried out with the help of 2D MHD code Enlil. The structure of the cloud at the isothermal stage of the collapse is investigated for the cases of weak, moderate, and strong initial magnetic field. Simulations reveal the universal hierarchical structure of collapsing protostellar clouds, consisting of flattened envelope with the qausi-magnetostatc disk inside and the first core in its center. The size of the primary disk increases with the initial magnetic energy of the cloud. The magnetic braking efficiently transports the angular momentum from the primary disk into the envelope in the case, when initial magnetic energy of the cloud is more than 20 % of its gravitational energy. Intensity of the outflows launched from the region near the boundary of the first core increases with initial magnetic energy. The `dead' zone with small ionization fraction, $x<10^{-11}$, forms inside the first hydrostatic core and at the base of the outflow. Ohmic dissipation and ambipolar diffusion determine conditions for further formation of the protostellar disk in this region.
