带有暗物质晕的Sgr A*和M87*的光学特征
Optical Signatures of Sgr A* and M87* with Dark Matter Halos
AI总结：
本研究探究冷暗物质与核心标量场暗物质晕对Sgr A*和M87*引力透镜特征的印记，发现两类黑洞临界曲线的拓扑差异可作为观测特征，且模型与EHT阴影直径数据吻合良好。
AI中文摘要：
事件视界望远镜（EHT）通过拍摄超大质量黑洞（SMBH）Sgr A*和M87*的阴影，为强场 regime 研究打开了新窗口，这些观测为探测黑洞周围的暗物质（DM）分布提供了独特实验室。本研究系统探究两种不同暗物质晕模型——冷暗物质（CDM）和核心标量场暗物质（SFDM）轮廓对Sgr A*和M87*引力透镜特征的印记，计算两种模型的光子球、阴影、弱和强透镜可观测值及焦散结构，随后利用χ²统计将所得阴影直径值与EHT数据对比。研究发现，所有模型的阴影直径均在测量值的1.2σ范围内，χ²差异较小，Δχ²≤1.2。焦散分析揭示了不同拓扑 regime：Sgr A*保留切向和径向临界曲线，而M87*因质量更大可能仅呈现切向临界曲线，这种拓扑差异为未来观测提供了明确的观测特征。
英文摘要：
The event horizon telescope (EHT) has opened a new window onto the strong-field regime by imaging the shadows of the supermassive black holes (SMBHs) Sgr A* and M87*. These observations provide a unique laboratory for probing the dark matter (DM) distribution around black holes. In this work we systematically investigate the imprints of two distinct DM halo models, the cold DM (CDM), and the cored scalar field DM (SFDM) profiles on the gravitational lensing signatures of Sgr A* and M87*. We compute the photon spheres, shadows, weak and strong lensing observables, and caustic structures for both models. We then compared the obtained values of the shadow diameters with the EHT data, using $χ^2$ statistics. We found that all the models are within $1.2σ$ of the measured shadow diameters with the small $χ^2$ differences, $Δχ^2 \lesssim 1.2$. The caustic analysis reveals distinct topological regimes, Sgr A* retains both tangential and radial critical curves, while M87* may show only tangential critical curves due to its larger mass. This topological difference provides a clear observational signature for future observations.
