X-ray echoes allows scientists to map out black holes: study

Researchers used X-ray echoes to map the surroundings of a black hole, revealing its spin and mass. They discovered that the black hole's corona changes size, affecting light echoes. This study was conducted using the European Space Agency's XMM X-ray Observatory.

What were the implications of the X-ray echoes observed by the team?

Describe the changes observed in the accretion disk of the black hole.