Stanford University professor Roger Blandford and his colleagues have recorded the so-called echo from the back of a supermassive black hole.

The gravity of ordinary and supermassive black holes is so strong that no objects or waves can reach us due to the event horizon. However, this can presumably be avoided by light particles that come very close to the event horizon. To do this, they must move in a specific direction relative to the event horizon.

In the new work, scientists obtained similar data using the orbiting X-ray telescopes NuSTAR and XMM-Newton, where there was information about a black hole from the center of the galaxy I Zw 1: the authors observed changes in intensity from the corona of the black hole and found a kind of echo that was delayed by about 12 minutes.

The authors believe that its source was the same interactions between the accretion disk and magnetic fields as earlier X-ray flares.

This means that the distance between the black hole’s corona and the event horizon is about four times that between the center point of the black hole and the event horizon.

Scientists plan to continue observations to understand how their magnetic fields and accretion disks interact with each other.