How the black hole may have reversed its entire magnetic field

Black holes contain a lot of energy in and around them. They also provide energy to quasars and other active Galaxy centres. Behind this there is an interaction of matter with the powerful gravitational field and magnetic field.

A black hole does not have a magnetic field of its own, but the plasma and charged particles that revolve around it produce an electric current and a magnetic field. The direction of flow of plasma never changes. In such a situation, scientists were very surprised when they saw the flipping of the magnetic field of a supermassive black hole.

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Swapping poles

In general terms, the magnetic field can be understood as the effect of a simple magnet that has north and south poles. When magnetic reversal occurs, the orientations of these imaginary poles are swapped. This effect is common in strings. But this is an unusual occurrence in a black hole.

Sun and Earth's magnetic field also rebounds

The same happens with our Sun also. The Sun's magnetic field rebounds every 11 years. This leads to an 11-year cycle that astronomers have been observing since the 17th century. Not only this, the Earth's magnetic field also changes every few million years. But no one had thought of such a magnetic rebound in a supermassive black hole.

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Where did this incident happen

In the year 2018, an automated celestial survey found that a sudden change is being seen in the galaxy located at a distance of 239 million light years. The luminosity of this galaxy named 1ES 1927+654 was 100 times that of visible light. Soon after its discovery, the Swift Observatory observed X-rays and ultraviolet rays in this glow.

Increase in brightness of X-rays and ultraviolet started in 2017

When astronomers looked at its old data, it was found that the increase in the brightness of X-rays and ultraviolet had started in the year 2017. It was initially believed that this brightness is due to a star located near the black hole of the Galaxy.

Such events were believed to give rise to tidal disruption events in which the star breaks apart and the effect of gas in the black hole's accretion cycle is disrupted. But a new study has rejected this idea.

Sudden change in X-ray intensity

In the new study, researchers studied the brightness of the galaxy by observing observations of the entire spectrum. They found that the intensity of X-rays was falling very fast. X-rays usually come from charged particles with a very strong magnetic field. From this it was found that a sudden change has been observed in the magnetic field near the black hole.

Storage disc overheating

At the same time, the intensity of visible and ultraviolet light also increased, which showed that parts of the black hole's accretion cycle were heating up. Neither of these two effects is seen in the tidal disruption event. But the idea of ​​a rebound in the magnetic field seems to be fitting.

The team showed that the field at the outer edges of the disk weakened before the magnetic rebound of the black hole's accretion disk, after which the disk would have heated up more effectively. At the same time, due to the weak magnetic field, fewer X-rays were being emitted.

Once the magnetic field completed its rebound, the disk returned to its original state. From this first observation, we have come to know that magnetic rebound also occurs in black holes. But we still do not know when this happens.

(With NASA Inputs)