An international team of astronomers has identified a candidate for the title of the smallest black hole known to us. The discovery was made using NASA’s orbiting observatories RXTE. This conclusion was based on the characteristic pattern of X-ray radiation, called "heartbeat" because of the resemblance to an electrocardiogram.
The find was named in accordance with their astronomical coordinates, IGR J17091-3624. This binary system is composed of a normal star and a black hole, which weighs three times smaller than our sun. This value is almost near the theoretical maximum mass at which the possible existence of a black hole.
Gas from the star is absorbed by the black hole and forms a disk around it. Friction within the disk heats the gas to a temperature of millions of degrees, it suffices to emit X-rays. Cyclical variations in the intensity of X-rays reflect the processes taking place within the gas disk.
Determine the distance to it is still not possible. Estimates vary widely, from 16,000 to 65,000 light-years from us.
"We believe that this is a pattern of radiation cycles of accumulation and eruptions of matter in an unstable disk, which we have already seen in the other black hole, IGR J17091", - said Tomaso Belloni of the Brera Observatory in Italy. "To find this figure in yet another system of a black hole is a very important event."
Changes in the X-ray spectrum during each heartbeat reveal that the inner region of the disk emits so much radiation that moves the gas around. This strong outgoing wind stops the flow of matter inside a short time draining black hole, followed by radiation out stops. The whole cycle takes only 5 seconds.
"Just as the heart rate exceeds that of the mouse at the elephant, the rate of" heartbeat "of black holes distributed according to their masses," - said Diego Altamirano of the University of Amsterdam.