标题： 关于相对论吸积盘的爱丁顿极限 显示英文标题

标题： On the Eddington limit for relativistic accretion discs

摘要： 标准吸积盘模型依赖于几个假设，其中最重要的是几何薄性。 当这一条件被违反时，新的物理效应变得重要，例如径向能量迁移和盘的质量损失。 这些效应在大质量吸积率情况下尤为重要，此时盘接近其局部爱丁顿极限。 在本工作中，我们研究标准吸积盘近似的上限，并找到在任何旨在再现超爱丁顿吸积区过渡的模型中应考虑的标准模型修正。 首先，我们发现对于薄吸积盘，考虑到相对论修正可以由于广义相对论（GR）中的更强引力而使局部爱丁顿极限增加约两倍。 然而，局部爱丁顿极限的违反也意味着盘的厚度较大。 为了连续考虑盘厚度的影响，必须对盘的二维旋转规律做出假设。 对于圆柱面上旋转频率恒定的$r\sin\theta=const$，在半径恒定的球面上，垂直引力随高度增强。 另一方面，径向通量迁移效应会增加盘内部区域的通量密度并降低爱丁顿极限。 一般来说，与盘厚度相关的效应倾向于进一步增加局部爱丁顿极限。 然而，迁移效应会使吸积效率降低约几倍。 显示英文摘要

摘要： Standard accretion disc model relies upon several assumptions, the most important of which is geometrical thinness. Whenever this condition is violated, new physical effects become important such as radial energy advection and mass loss from the disc. These effects are important, for instance, for large mass accretion rates when the disc approaches its local Eddington limit. In this work, we study the upper limits for standard accretion disc approximation and find the corrections to the standard model that should be considered in any model aiming on reproducing the transition to super-Eddington accretion regime. First, we find that for thin accretion disc, taking into account relativistic corrections allows to increase the local Eddington limit by about a factor of two due to stronger gravity in General Relativity (GR). However, violation of the local Eddington limit also means large disc thickness. To consider consequently the disc thickness effects, one should make assumptions upon the two-dimensional rotation law of the disc. For rotation frequency constant on cylinders $r\sin\theta=const$, vertical gravity becomes stronger with height on spheres of constant radius. On the other hand, effects of radial flux advection increase the flux density in the inner parts of the disc and lower the Eddington limit. In general, the effects connected to disc thickness tend to increase the local Eddington limit even more. The efficiency of accretion is however decreased by advection effects by about a factor of several.