First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
复制标题
第一个 M87 事件视界望远镜结果。
DOI：
10.3847/2041-8213/ab0f43
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发表时间：
2019-04-10
影响因子：
7.9
通讯作者：
Zhang, Shuo
中科院分区：
文献类型：
--
作者：
Akiyama, Kazunori;Alberdi, Antxon;Zhang, Shuo
事件视界望远镜（EHT）以前所未有的角分辨率绘制了椭圆星系M87的1.3毫米中央致密射电源。在这里，我们考虑了2017年EHT数据中看到的不对称环的物理含义。为此，我们构建了一个大型库的模型的基础上，广义相对论磁流体动力学（GRMHD）模拟和合成图像产生的广义相对论射线追踪。我们比较观察到的vibrium与这个库，并确认不对称环是一致的，从黑洞事件视界附近的热等离子体轨道的同步辐射的强引力透镜的早期预测。环的半径和环的不对称性分别取决于黑洞的质量和自旋，因此在未来的EHT活动中，两者都有望保持稳定。总的来说，观测到的图像与广义相对论预测的旋转克尔黑洞阴影的预期一致。如果黑洞的旋转和M87的大尺度喷流是一致的，那么黑洞的旋转矢量就指向远离地球的方向。我们的非旋转黑洞库中的模型与观测结果不一致，因为它们没有产生足够强大的喷流。同时，在那些产生足够强大的喷流的模型中，后者是通过类似于Blandford-Znajek过程的机制提取黑洞自旋能量来提供动力的。我们简要地考虑中央致密物体的黑洞的替代品。对现有的EHT偏振数据和在其他波长同时采集的数据进行分析，将很快使GRMHD模型的新测试成为可能，未来在230和345 GHz的EHT活动也将如此。
The Event Horizon Telescope (EHT) has mapped the central compact radio source of the elliptical galaxy M87 at 1.3 mm with unprecedented angular resolution. Here we consider the physical implications of the asymmetric ring seen in the 2017 EHT data. To this end, we construct a large library of models based on general relativistic magnetohydrodynamic (GRMHD) simulations and synthetic images produced by general relativistic ray tracing. We compare the observed visibilities with this library and confirm that the asymmetric ring is consistent with earlier predictions of strong gravitational lensing of synchrotron emission from a hot plasma orbiting near the black hole event horizon. The ring radius and ring asymmetry depend on black hole mass and spin, respectively, and both are therefore expected to be stable when observed in future EHT campaigns. Overall, the observed image is consistent with expectations for the shadow of a spinning Kerr black hole as predicted by general relativity. If the black hole spin and M87's large scale jet are aligned, then the black hole spin vector is pointed away from Earth. Models in our library of non-spinning black holes are inconsistent with the observations as they do not produce sufficiently powerful jets. At the same time, in those models that produce a sufficiently powerful jet, the latter is powered by extraction of black hole spin energy through mechanisms akin to the Blandford-Znajek process. We briefly consider alternatives to a black hole for the central compact object. Analysis of existing EHT polarization data and data taken simultaneously at other wavelengths will soon enable new tests of the GRMHD models, as will future EHT campaigns at 230 and 345 GHz.