事件视界望远镜对近邻星系M87中心超大质量黑洞的成像观测  

First EHT images of the supermassive black hole residing in the center of nearby galaxy M87

作　　者：袁业飞 唐泽源 Yefei Yuan;Zeyuan Tang(Department of Astronomy,School of Physical Sciences,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学物理学院天文学系

出　　处：《科学通报》2019年第20期2072-2076,共5页Chinese Science Bulletin

基　　金：国家自然科学基金(11725312)资助

摘　　要：2019年4月10日21时,天文学家公布了人类首次拍摄到的近邻椭圆星系M87中心黑洞在1.3mm波段的成像观测结果,看到黑洞视界的阴影,直接证明了黑洞的存在.黑洞是广义相对论关于时空和引力理论的伟大理论预言.直接证明黑洞的存在,不仅可以检验广义相对论的正确性,而且可以研究黑洞强引力场中的物理过程,解释相应的天文现象.In 1915, Albert Einstein published his famous field equation of gravitation, which marked the formal establishment of general relativity. Shortly after the publication of Einstein’s field equation, Karl Schwarzschild found its first solution, which describes the curved spacetime outside of a spherically symmetric object with gravitational mass M. If the gravitational mass M is concentrated at one point, i.e., the singularity, then the object is a non-rotating black hole-a Schwarzschild black hole. The most essential feature of a black hole is the existence of event horizon which is a one-way causal boundary in spacetime, that is, the most inner region linking with a distant observer at infinity. Even light can not escape from the event horizon of a black hole. For Schwarzschild black hole, the size of its horizon is proportional to its gravitational mass: Rs=2 M(G=c=1). Due to the effects of the curved spacetime, such as the gravitational lensing and photon capture at the event horizon, the apparent radius of a black hole shadow is about √27M. For a rotating black hole, the size of its shadow also depends on its spin, so the radius of the black hole shadow is between 4.8 M and 5.2 M. The massive black holes in the center of Milky Way and the nearby giant elliptical galaxy M87(Sgr A* and M87*) are the two biggest ones on the celestial sphere, and the angular sizes of their shadows are about 26.7 and 18.8 μas, respectively. Multi-wavelength observations show that both Sgr A* and M87* swallow surrounding gas with a very low accretion rate, the radio emission from Sgr A* and M87* is mainly due to the synchrotron emission from hot plasma orbiting around their event horizons. The Event Horizon Telescope(EHT), a global very-long-baseline interferometry array observing at a wavelength of 1.3 mm, has a theoretical diffraction-limit resolution of ~25 μas, so Sgr A* and M87* are first two targets of EHT. At 21:00 on April 10, 2019(Beijing Time), the first EHT image of M87* was released. It shows an asymmetric bright e

关 键 词：中心黑洞 近邻星系 事件视界 观测 成像 望远镜 广义相对论 质量 

分 类 号：P145.8[天文地球—天体物理]