银河系的黑洞

2022年5月13日

The Milky Way’s Black Hole
Image Credit: X-ray – NASA/CXC/SAO, IR – NASA/HST/STScI; Inset: Radio – Event Horizon Telescope Collaboration

Explanation: There’s a black hole at the center of the Milky Way. Stars are observed to orbit a very massive and compact object there known as Sgr A* (say “sadge-ay-star”). But this just released radio image (inset) from planet Earth’s Event Horizon Telescope is the first direct evidence of the Milky Way’s central black hole. As predicted by Einstein’s Theory of General Relativity, the four million solar mass black hole’s strong gravity is bending light and creating a shadow-like dark central region surrounded by a bright ring-like structure. Supporting observations made by space-based telescopes and ground-based observatories provide a wider view of the galactic center’s dynamic environment and an important context for the Event Horizon Telescope’s black hole image. The main panel image shows the X-ray data from Chandra and infrared data from Hubble. While the main panel is about 7-light years across, the Event Horizon Telescope inset image itself spans a mere 10 light-minutes at the center of our galaxy, some 27,000 light-years away.

Tomorrow’s picture: ice halos by moonlight

银河系的黑洞
影像提供: X-ray: NASA/CXC/SAO, IR: NASA/HST/STScI – Inset: Radio (EHT Collaboration)

说明: 银河系的中心有个黑洞。从恒星观测，可知这些恒星绕著名为Sgr A*（读音为sadge-ay-star；人马A）的极大质量致密天体运行。而地球事件视界望远镜刚发布的这张电波影像（嵌图），则提供银河中心黑洞存在的首个直接证据。正如同爱因斯坦的广义相对论所预测，质量为4百万倍太阳的黑洞之强大引力正在弯曲光线，并形成一个暗影般的黝黑中心区，其周围环绕着一个明亮的环状结构。而太空望远镜和地基天文台所进行的协同观测，为银河系中心的动态环境提供了更广阔的视野，并为事件视界望远镜的黑洞影像提供了重要背景。主图板影像则呈现钱德拉的X射线数据和哈勃的红外数据。虽然主图的宽度约为7光年，但事件视界望远镜嵌图在我们银河系距离我们约27,000光年远的中心之跨幅仅有10光分。

明日的图片: ice halos by moonlight