标题： 非轴对称的相对论性Bondi-Hoyle吸积到Kerr黑洞 显示英文标题

标题： Non-axisymmetric relativistic Bondi-Hoyle accretion onto a Kerr black hole

摘要： 在我们研究所谓的Bondi-Hoyle吸积在完全相对论区域中的程序中，我们在此呈现关于物质以超音速吸积到旋转（Kerr）黑洞上的初步结果。 这些计算推广了之前的结果，在那些结果中非旋转的（Schwarzschild）情况得到了广泛考虑。 我们通过流体的渐近条件来参数化初始数据，并探讨解对黑洞角动量的依赖性。 为了量化数值结果的鲁棒性，我们使用了两种不同的黑洞时空几何切片，标准形式的Kerr度规在Boyer-Lindquist坐标中以及其Kerr-Schild形式，后者在黑洞视界处没有坐标奇点。 我们展示了使用这种与视界适应的坐标系统的某些重要优势。 我们的数值研究显示，无论黑洞自旋的值如何，最终的吸积模式总是稳定的，导致质量和动量的恒定吸积率。 该流动由一个强烈的尾部激波特征，与Schwarzschild情况不同，随着黑洞角动量的增加，该激波会越来越多地环绕中心黑洞。 压力场中的旋转引起的不对称性意味着除了众所周知的阻力外，黑洞还会经历一个垂直于流动方向的升力。 这种情况与经典流体力学中的马格努斯效应有一些相似之处。 显示英文摘要

摘要： In our program of studying numerically the so-called Bondi-Hoyle accretion in the fully relativistic regime, we present here first results concerning the evolution of matter accreting supersonically onto a rotating (Kerr) black hole. These computations generalize previous results where the non-rotating (Schwarzschild) case was extensively considered. We parametrize our initial data by the asymptotic conditions for the fluid and explore the dependence of the solution on the angular momentum of the black hole. Towards quantifying the robustness of our numerical results, we use two different geometrical foliations of the black hole spacetime, the standard form of the Kerr metric in Boyer-Lindquist coordinates as well as its Kerr-Schild form, which is free of coordinate singularities at the black hole horizon. We demonstrate some important advantages of using such horizon adapted coordinate systems. Our numerical study indicates that regardless of the value of the black hole spin the final accretion pattern is always stable, leading to constant accretion rates of mass and momentum. The flow is characterized by a strong tail shock, which, unlike the Schwarzschild case, is increasingly wrapped around the central black hole as the hole angular momentum increases. The rotation induced asymmetry in the pressure field implies that besides the well known drag, the black hole will experience also a lift normal to the flow direction. This situation exhibits some analogies with the Magnus effect of classical fluid dynamics.