A STUDY ON MECHANISM AND STRUCTURE OF RELATIVISTIC STELLAR WIND FROM ROTATING MAGNETOSPHERES

本项目的主要目的是阐明空间中旋转的强磁化物体喷射出的相对论性等离子体的加速效率。效率是由在恒星风的根部占主导地位的电磁能量通量的多少部分转化为等离子体动能来定义的。在这个项目的第一年，我们大致解决了磁场结构，这被认为是控制效率的因素。这是通过解决所谓的“Grad-Shafranov”方程来实现的。我们得到了类似于恒星附近双子星的场结构，并逐渐修正为径向相似的开放结构。第二年，在得到的场结构下求解场对准方程，得到效率。选择场对准溶液，使其从等离子体源出发，通过阿尔芬临界点，然后通过快速临界点。已经知道，如果场结构是完全径向的，等离子体是冷的，那么快临界点在无穷远处，效率很小。相反，在本项目获得的场结构下，我们发现快临界点向内移动到光柱附近，并且获得了非常高的效率。观测中，蟹状星云脉冲星的相对论风显示出很高的效率，所以我们的理论可以解释这个观测结果。

The main aim of this project is to clarify the effeciency of acceleration of the relativistic plasma outflow which is ejected from the rotating strongly magnetized objects in space. The efficiency is defined by how much fraction of the electromagnetic energy flux, which is dominant at the root of the stellar wind, is converted into plasma kinetic energy.At the fisrt year of this project, we approximately solved the magnetic field structure, which is believed to govern the efficiency. This is done by solving the so-called 'Grad-Shafranov' equation. We have obtained the field structure which is like the diple near the star and gradually modifed to the radial-alike open structure.At the second year, the field-aligned equation is solved under the obtained field structure in orger to get the efficiency. The field-aligned solution is chosed so that it start from the plasma source, passes throught the Alfven-critical point, and then passes throught the fast-critical point. It has been known that if the field structure is perfectly radial and the plasma is cold, then the fast-critical point is at infinity, and the efficiency is quite small. Contrarily, under the field structure we obtained in this project, we find that the fast-critical point moved inward to near the light cylinder, and very hight efficiency is obtained.Observationary, the relativistic wind from the Crab pulsar shows a high efficiency so our theory may account for this observational result.