Question

what is black bath of the black hole is
called​

Answer 1

Any light that crosses its event horizon is forever trapped. The glowing ring we see in the EHT image of M87* is caused by the background radio glow of gas and dust surrounding the black hole. Some of that light passes very close to the black hole and is gravitationally lensed in our direction

Answer 2

Answer:

There are two basic parts to a black hole: the singularity and the event horizon. The event horizon is the "point of no return" around the black hole. It is not a physical surface, but a sphere surrounding the black hole that marks where the escape velocity is equal to the speed of light.