Astronomers at the University of Leicester have recorded for the first time the fall of matter into a supermassive black hole at a speed equal to 30 percent of the speed of light. This indicates that the plasma orbiting the hole does not form a flat accretion disk, but a complex structure of chaotic rings. The article of scientists was published in the journal Royal Astronomical Society.
PG211 + 143, more than a billion light-years distant from Earth, is a Seyfert galaxy, that is, a galaxy with an active core that releases a huge amount of energy. In the center of the core is a feeding supermassive black hole, around which there is a disk of rapidly rotating matter. This disk emits powerful electromagnetic radiation that exceeds the Eddington limit, that is, the strength of the emerging fields in some areas exceeds the gravitational forces of the black hole. The result is ultrafast outflows (UFOs) of plasma that reach 0.2 times the speed of light.
Data from the XMM-Newton Space Telescope and other instruments have shown that the inner disk around the black hole has a complex structure, causing ultra-fast ejections from different regions to develop at different speeds. Previous studies have suggested that some of these ejections may fall directly into a black hole, challenging the notion of a flat accretion disk, in which matter slowly spirals toward the event horizon.
Calculations show that the disks in active galactic nuclei are affected by the forces arising from the Lense-Thirring effect, which is observed near rotating massive bodies. Additional accelerations appear, similar to the Coriolis acceleration. As a result, the disc bursts into separate rings of gas, which begin to shift randomly. These rings can collide with each other, as a result, the matter in them loses speed and falls into a black hole. In this case, the residual angular momentum, which characterizes the rotational motion, can allow the gas to form a disc of a smaller radius.
Scientists analyzed data obtained with the XMM-Newton Space Telescope and found evidence of a short-lived plasma stream directed into a black hole at 0.3 times the speed of light. This proves that accretion disks are indeed capable of splitting.
Astronomers note that this chaotic accretion keeps the black hole from spinning and allows it to grow rapidly. This would help solve the problem of supermassive black holes in the early Universe, which, according to one hypothesis, emerged from large "embryos" - black holes directly formed from giant clouds of gas or from the collapse of especially large stars. The research results show that such massive embryos are not necessary.