The study of the mysterious corona of a black hole formed by X-rays presented an interesting discovery. Space telescopes XMM-Newton and NuSTAR were able to "see" the light reflected by matter just behind the incredibly massive object. And although this once again confirms the general theory of relativity, scientists have received almost no new data about the main object of research.
The first known detection of light reflected by matter directly behind a black hole was reported by an international team of scientists led by Dan Wilkins of Stanford University (USA). The researchers processed data from two space observatories of the European Space Agency (ESA) and the US National Aeronautics and Space Administration (NASA) - XMM-Newton and NuSTAR. The main object of study was the black hole in the center of the galaxy I Zwicky 1, located about 800 million light years from us.
Like many similar objects, this black hole has a corona emanating from those regions of it that can be called "up" and "down" when viewed in the plane of the accretion disk. The most reliable mechanism of its formation is as follows. The material in the disk falls onto the black hole and accelerates to incredible speeds, which causes it to heat up. This leads to the formation of powerful magnetic fields directed in directions perpendicular to the plane of the disk. Their lines get tangled, stretched and reconnected at some point.
This phenomenon leads to the release of a huge amount of energy, usually in the form of electrons. And they, in turn, emit photons in the X-ray range. The result is powerful torch-like streams emanating from the black hole's poles that are visible through half the universe. Some of this light is reflected from the surrounding matter (mainly in the accretion disk) and scattered. It is this echo that was captured by near-Earth telescopes.
A black hole is such a massive object that it distorts space-time, creating bizarre effects. Many of them are predicted by general relativity, for example - gravitational lensing. Astronomers often use it to obtain information on extremely distant objects, the light of which passes through such distortions on the way to Earth and is amplified. Usually, however, the distance between the radiation source, the "lens" and the Earth is estimated at millions of light years. But to see the light redirected by the black hole, which is emitted (or reflected) by the matter directly behind it, has never been possible.
There is no doubt that this is precisely corona radiation reflected by the disk behind the black hole. Its spectrum and time of receipt are somewhat different from that tempted by the "torch" or by the crown itself. Exactly those values that correspond to the distance traveled and the interaction with the matter of the disk. In the future, Wilkins' team plans to use the phenomenon they discovered to create a three-dimensional picture of the closest environment of a black hole. True, in this whole story there is also one reason for frustration - almost no new data have been received about the main object of astrophysics study.