Self-lensing flares from black hole binaries: General-relativistic ray tracing of black hole binaries
Self-lensing flares from black hole binaries: General-relativistic ray tracing of black hole binaries
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DOI：
10.1103/physrevd.105.103010
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发表时间：
2021-12
影响因子：
5
通讯作者：
J. Davelaar;Z. Haiman
中科院分区：
文献类型：
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作者：
J. Davelaar;Z. Haiman
当两个黑洞双星在视线附近对准时，大质量黑洞双星(MBHB)的自透镜效应预计会产生周期性的、持续时间较短的耀斑。在叠加的二元BH度规中，我们通过广义相对论光线追迹研究了自透镜耀斑(SLF)的形状，在该度规中，辐射是由围绕每个分量的几何薄吸积流产生的。这套模型涵盖了偏心双星轨道、黑洞自转、不等质量双星和不同的发射模型几何形状。我们探索上述参数空间，并报告光曲线如何作为例如二元分离、倾斜和偏心的函数而变化。我们还将我们的光曲线与微透镜近似中的光曲线进行了比较，并展示了强烈的偏转以及时延效应如何改变了SLF的大小和形状。如果LISA观测到来自激动人心的MBHB的引力波(GW)，SLF可以帮助安全地识别源并将其定位在天空中，并通过比较SLF和GWS的相位来约束引力子质量。此外，当从侧面观察这些系统时，SLF显示出一个明显的倾角，这可以直接与BH阴影大小相关。这开辟了一种新的方法来测量当前VLBI设施无法解决的系统中的BH阴影大小。
The self-lensing of a massive black hole binary (MBHB), which occurs when the two BHs are aligned close to the line of sight, is expected to produce periodic, short-duration flares. Here we study the shapes of self-lensing flares (SLFs) via general-relativistic ray tracing in a superimposed binary BH metric, in which the emission is generated by geometrically thin accretion flows around each component. The suite of models covers eccentric binary orbits, black hole spins, unequal mass binaries, and different emission model geometries. We explore the above parameter space, and report how the light curves change as a function of, e.g., binary separation, inclination, and eccentricity. We also compare our light curves to those in the microlensing approximation, and show how strong deflections, as well as time-delay effects, change the size and shape of the SLF. If gravitational waves (GWs) from the inspiraling MBHB are observed by LISA, SLFs can help securely identify the source and localizing it on the sky, and to constrain the graviton mass by comparing the phasing of the SLFs and the GWs. Additionally, when these systems are viewed edge-on the SLF shows a distinct dip that can be directly correlated with the BH shadow size. This opens a new way to measure BH shadow sizes in systems that are unresolvable by current VLBI facilities.