When mass falls on the polar regions of a neutron star in a binary X-ray source system, it tends to spread out over the entire surface. A long-standing question in research on this problem is: will the mass be anchored on the magnetic field lines and drag the field with it or is there a special mechanism that allows the mass to slip through the magnetic field lines, leading to much less distortion? As the amount of mass falling on the neutron star can actually be comparable with the neutron star mass, the question of which alternative holds is very important. We suggest an efficient mechanism that will allow the mass to slip through the lines. The mechanism is based on a strong ideal Schwarzschild (Structure and Evolution of the Stars. Princeton University Press, 1958) instability. As the instability itself is ideal, it cannot directly force the mass to slip though the lines. However, it can create a cascade of eddies whose scale extends down to a resistive scale, at the same time mixing the field lines up without breaking them. On this scale the mass can cross the lines. This instability is efficient enough that it can produce a mass flow in the plasma without growing to a large amplitude but saturates at a small one. The instability determines the mass per flux distribution of the accumulated material on different lines so that the equilibrium is marginal to the instability on every line. This makes the equilibrium unique. Thus, as the extra mass on the neutron star grows, the state of the outer shell proceeds through a sequence of unique critically unstable equilibria. In an appendix, an attempt is made to track the critical equilibria over long times.

中文翻译：

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吸积中子星中太高斯磁场的异常扩散

当质量落在双星 X 射线源系统中的中子星的两极区域时，它往往会散布在整个表面上。研究这个问题的一个长期存在的问题是：质量是否会锚定在磁力线上并拖动磁场，或者是否有一种特殊的机制可以让质量滑过磁力线，导致更少失真？由于落在中子星上的质量实际上可以与中子星的质量相媲美，因此哪种选择成立的问题非常重要。我们提出了一种有效的机制，可以让质量滑过线。该机制基于强理想史瓦西 (恒星的结构与演化. 普林斯顿大学出版社，1958 年）不稳定。由于不稳定性本身是理想的，它不能直接迫使质量滑过线。然而，它可以产生级联的涡流，其尺度向下延伸到电阻尺度，同时混合场线而不破坏它们。在这个规模上，质量可以跨越界限。这种不稳定性足够有效，它可以在等离子体中产生质量流，而不会增长到很大的幅度，但会在很小的幅度下饱和。不稳定性决定了不同线上累积材料的每通量质量分布，因此平衡对每条线上的不稳定性都是边缘的。这使得平衡是独一无二的。因此，随着中子星上额外质量的增长，外壳的状态会经历一系列独特的临界不稳定平衡。