How do scientists look for black holes in the sky

To find black holes in space, scientists use telescopes to study visible light, X-rays, and radio waves. When gas orbits a black hole, it gets very hot and starts emitting X-rays and radio waves. Through special telescopes, the area surrounding the black hole looks really bright.

Scientists look through special telescopes and the area surrounding the black hole is suppose to look really bright.

layer a is the exosphere and layer b is the thermosphere.   is the answer i think but i hope this .