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arXiv 1906.11241astro-ph.GAastro-ph.IMgr-qc
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第一个M87事件视界望远镜的结果。IV。中心超大质量黑洞的成像

First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole

The Event Horizon Telescope Collaboration

摘要:

我们展示了M87的第一张事件视界望远镜(EHT)图像,使用了2017年4月在1.3 mm波长下的观测结果。这些图像显示了一个直径约为40微阿斯的突出环,与环绕超大质量黑洞“阴影”的透镜光子轨道的大小和形状一致。该环在四个观测夜晚持续存在,并在南部显示出增强的亮度。为了评估这些结果的可靠性,我们实施了两阶段成像程序。在第一阶段,四个团队,每个人都不知道其他人的工作,使用一种既定的方法(CLEAN)和一种较新的技术(正则化极大似然)制作M87的图像。这一阶段使我们能够避免共同的人类偏见,并评估独立重建之间的共同特征。在第二阶段,我们重建合成数据从一个大的调查成像参数,然后比较结果与相应的地面实况图像。这一阶段使我们能够客观地选择参数,以便在重建M87图像时使用。在两个阶段的所有测试中,环直径和不对称性保持稳定,对成像技术的选择不敏感。我们描述的EHT成像程序,在M87的主要图像功能,以及这些功能的依赖成像假设。

英文摘要:

We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ~40 micro-as, consistent with the size and shape of the lensed photon orbit encircling the "shadow" of a supermassive black hole. The ring is persistent across four observing nights and shows enhanced brightness in the south. To assess the reliability of these results, we implemented a two-stage imaging procedure. In the first stage, four teams, each blind to the others' work, produced images of M87 using both an established method (CLEAN) and a newer technique (regularized maximum likelihood). This stage allowed us to avoid shared human bias and to assess common features among independent reconstructions. In the second stage, we reconstructed synthetic data from a large survey of imaging parameters and then compared the results with the corresponding ground truth images. This stage allowed us to select parameters objectively to use when reconstructing images of M87. Across all tests in both stages, the ring diameter and asymmetry remained stable, insensitive to the choice of imaging technique. We describe the EHT imaging procedures, the primary image features in M87, and the dependence of these features on imaging assumptions.

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。

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