标题： 等质量大质量黑洞双星的mini盘辐射磁流体力学模拟 显示英文标题

标题： Radiative magnetohydrodynamics simulation of minidisks in equal-mass massive black hole binaries

摘要： 我们即将利用激光干涉空间天线和脉冲星计时阵列探测到来自单个大质量黑洞双星（MBHB）的引力波（GW）。这些MBHB可能被周围的环双星盘和小盘环绕，它们的电磁辐射对于在天空中定位MBHB至关重要。在这里，我们提出了第一个直接求解离散网格射线辐射转移方程的辐射磁流体力学（RMHD）小盘模拟。该模拟研究了由100个引力半径分离的等质量$2\times10^7\,M_\odot$MBHB之一的小盘。带有和不带辐射效应的小盘在定性上相似，但在几个关键方面有所不同。RMHD小盘比磁流体力学小盘更密集且几何上更薄。此外，具有非轴对称视界和温度分布的RMHD小盘产生了一种各向异性的照明模式。因此，两个相互绕转的RMHD小盘的观测辐射通量以二元轨道周期的一半变化，这一特征独立于相对论增强和透镜效应。如果在即将到来的光学瞬变巡天中识别出这种周期性光曲线，则可以揭示正在合并的MBHB的存在，尤其是如果它们与检测到的GW处于恒定相位关系中。 显示英文摘要

摘要： We are on the cusp of detecting gravitational waves (GWs) from individual massive black hole binaries (MBHBs) with the Laser Interferometer Space Antenna and pulsar-timing arrays. These MBHBs may be surrounded by circumbinary disks and minidisks, the electromagnetic emission from which are essential for localizing the MBHBs on the sky. Here we present the first radiative magnetohydrodynamics (RMHD) minidisk simulation that directly solves the radiative transfer equation on discretized grid rays. The simulation examines one of the minidisks in an equal-mass $2\times10^7\,M_\odot$ MBHB separated by 100 gravitational radii. Minidisks simulated with and without radiative effects resemble each other qualitatively but differ in several key aspects. The RMHD minidisk is denser and geometrically thinner than the magnetohydrodynamics minidisk. Furthermore, the RMHD minidisk, with a nonaxisymmetric photosphere and temperature distribution, produces an anisotropic illumination pattern. As a result, the observed radiative flux of two RMHD minidisks orbiting each other varies at half the binary orbital period, a feature independent of relativistic boosting and lensing effects. Such periodic light curves, if identified in upcoming optical transient surveys, could reveal the existence of MBHBs on the way to merger, particularly if they are in a constant phase relation with detected GWs.