Samuzal Barua

X-rays from the vicinity of a black hole don't arrive all at once. Some of them first fall onto a disk of scorching gas, get reflected, and only then travel to the telescope. This delay is like an echo in the mountains: first you hear the direct sound, then the response from the cliff.

At the center of the galaxy Ton S180 lurks a black hole that occasionally flares in X-rays. These flares are like a flashlight beam shining onto a swirling disk of superheated gas. Part of the light heads straight toward us, while another part first hits the disk, bounces off, and only then reaches the telescope.