拉格朗日点附近黑洞阴影的毫米波轨道高分辨率成像
High Resolution Imaging of a Black Hole Shadow with Millimetron Orbit around Lagrange Point L2
摘要：
超大质量黑洞（SMBH）视界阴影的甚长基线干涉测量（VLBI）是近年来被公认为检验爱因斯坦广义相对论的有力工具。事件视界望远镜（EHT）已经证明，具有最大长基线（$D=10,700$ km）的地球扩展VLBI可以提供足够的角分辨率$θ\sim 20~μ$，如$λ=1.3$ mm（$ν=230$ GHz），用于成像位于星系M87 $^\ast$中的SMBH周围的阴影。然而，诸如阴影周围的新月形明亮结构的不对称性以及阴影底和明亮新月形轮廓之间的过渡区的锐度（两者都是$Δθ\sim 4~μ$级）之类的至关重要的特征的精度仍有待提高。在我们以前的论文中，我们已经表明，在近地高椭圆轨道（HEO）的联合毫米波和EHT配置的空间-地球VLBI观测可以大大提高图像质量。利用毫米波和EHT联合计划在日地系统拉格朗日点L2处获得的更高分辨率，以及$Δθ\sim 5~μ$在230~GHz处的预期成像分辨率，可以为广义相对论的可靠实验验证提供更坚实的基础。在本文中，我们认为，尽管L2轨道的限制，一个足够的稀疏$(u,v)$覆盖范围可以实现和Sgr A $^\ast$和M87 $^\ast$周围的阴影成像可以进行合理的质量。
英文摘要：
Imaging of the shadow around supermassive black hole (SMBH) horizon with a very long baseline interferometry (VLBI) is recognized recently as a powerful tool for experimental testing of Einstein's General relativity. The Event Horizon Telescope (EHT) has demonstrated that an Earth-extended VLBI with the maximum long base ($D=10,700$ km) can provide a sufficient angular resolution $θ\sim 20~μ$as at $λ=1.3$ mm ($ν=230$ GHz) for imaging the shadow around SMBH located in the galaxy M87$^\ast$. However, the accuracy of critically important characteristics, such as the asymmetry of the crescent-shaped bright structure around the shadow and the sharpness of a transition zone between the shadow floor and the bright crescent silhouette, both of order $Δθ\sim 4~μ$as, is still to be improved. In our previous paper we have shown that Space-Earth VLBI observation within a joint Millimetron and EHT configuration at the near-Earth high elliptical orbit (HEO) can considerably improve the image quality. Even more solid grounds for firm experimental validation of General relativity can be obtained with a higher resolution available within the joint Millimetron and EHT program at the Lagrangian point L2 in the Sun-Earth system with an expected imaging resolution at 230~GHz of $Δθ\sim 5~μ$as. In this paper we argue that in spite of limitations of L2 orbit, an adequate sparse $(u,v)$ coverage can be achieved and the imaging of the shadows around Sgr A$^\ast$ and M87$^\ast$ can be performed with a reasonable quality.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
