2022年5月1日
First Horizon-Scale Image of a Black Hole
Image Credit: Event Horizon Telescope Collaboration
Explanation: What does a black hole look like? To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky. Alone, black holes are just black, but these monster attractors are known to be surrounded by glowing gas. This first image resolves the area around the black hole at the center of galaxy M87 on a scale below that expected for its event horizon. Pictured, the dark central region is not the event horizon, but rather the black hole’s shadow — the central region of emitting gas darkened by the central black hole’s gravity. The size and shape of the shadow is determined by bright gas near the event horizon, by strong gravitational lensing deflections, and by the black hole’s spin. In resolving this black hole’s shadow, the Event Horizon Telescope (EHT) bolstered evidence that Einstein’s gravity works even in extreme regions, and gave clear evidence that M87 has a central spinning black hole of about 6 billion solar masses. Since releasing this featured image in 2019, the EHT has expanded to include more telescopes, observe more black holes, track polarized light,and is working to observe the immediately vicinity of the black hole in the center of our Milky Way Galaxy.
This week is: Black Hole Week
New EHT Results to be Announced: Next Thursday
Tomorrow’s picture: crescent sun
首张黑洞事件视界尺度的影像
影像提供: Event Horizon Telescope Collaboration
说明: 黑洞长什么样子？为了找出答案，地球各地的电波望远镜，针对天空已知具有最大事件视界的黑洞，进行了协调合作观测。一颗孤伶伶的黑洞是全黑的，但是这些吸引力超强的宇宙怪兽，周围都环绕着发光的气体。在2019年4月发布的首张影像，解析出位在星系M87核心的黑洞附近，尺度比它预期的事件视界规模小的区域。影像中的黝黑中心区并不是事件视界，而是黑洞的阴影，因为这个中心区气体发出的辉光有部分被黑洞的重力给吞噬了。阴影的大小和形状，则受到事件视界附近的明亮气体、强大重力透镜造成的偏折、与黑洞自转的影响。事件视界望远镜（EHT）解析出黑洞阴影的这项成果，除了为爱因斯坦的重力理论，在这种极端区域仍然适用提供了佐证，更清楚指证星系M87的中心，有颗质量约高达60亿倍太阳的自转黑洞。自从在2019年发布这幅主题影像之后，事件视界望远镜扩大规模增加更多望远镜、观测更多黑洞，追踪极化光、及正在观测紧临我们系中心黑洞的区域。
本周是: 黑洞周
将公布新的EHT结果: 下周四
明日的图片: crescent sun