Speaking of the most powerful and mysterious black hole in the universe, what kind of image will emerge in your mind?
In general films and popular science works, it is often like this: a huge accretion disk rotates around a black hole, with high-speed jet streams at both ends, and all cosmic matter and even light are ruthlessly sucked into it.
In April this year, the first black hole photo in human history was released. Although it was very vague, we finally "saw" the black hole.
Now, with a rigorous scientific attitude, NASA has drawn a clear face of black holes, a distorted and magnificent world.
Gif dynamic diagram
This is a system composed of black hole body, light, accretion disk, etc. each part is explained in detail as follows:
The black part in the middle is not a black hole, but just the black hole shadow, which is about twice the event horizon.
The thin circle of light outside it is called the photon ring. It is an 'aperture' formed after the accretion disk image is distorted many times. The light is often distorted by the black hole twice, three times or even more before it can be seen by the outside world, and becomes darker and weaker because it is too close to the black hole.
The whole periphery revolves around the black hole, which is a huge accretion disk. It is a hot and thin layer, which is composed of various substances and gases rotating at high speed and falling slowly to the black hole. It becomes extremely bright due to strong collision and radiation.
The accretion disk is originally a normal disk shape, but because the light near the black hole is highly distorted, the accretion disk we see becomes what it looks like in the picture.
Above is actually the far end of the accretion disk. The gravitational field of the black hole distorts the light propagation path at the far end, making it seem to stand up and be seen by us.
The lower part is the bottom of the far end of the accretion disk. It is also because the light is distorted by the gravitational field of the black hole. It belongs to a lens effect. However, it looks smaller and incomplete than the upper part because it needs to be bypassed from the 'lower part' of the black hole.
In addition, it can be seen that the image on the left side of the accretion disk is much brighter than that on the right side. This is because it is assumed that the accretion disk rotates counterclockwise, and the material on the left side moves at a high speed towards the observer. It becomes bright due to the Doppler effect, and the far away on the right side becomes dim.
If you have seen the movie interstellar, you will find that this picture of NASA looks very familiar, because the black hole in that film is basically like this. It is also the first time in history that such a scientific (to the knowledge of mankind) real black hole is displayed in film and television works, and rigorous scientific teams are invited to calculate and render it.