Black holes are some of the most mysterious objects in the universe.
They have such strong gravity that not even light can escape them.
Around a black hole, gas and dust swirl at high speeds, forming what’s called an accretion disk.
These disks emit huge amounts of energy in the form of light and plasma jets, making them one of the most efficient energy sources in the universe.
However, black holes aren’t just sitting still—they often spin, and their spin can influence the behavior of the accretion disk around them.
Researchers from the University of Tsukuba have found the first evidence that the spin of a black hole causes a wobbling motion, or precession, in ultraluminous accretion disks.
These disks, made of gas swirling around black holes, are known for emitting powerful light and plasma jets.
While precession has been observed in less luminous accretion disks, this is the first time it has been demonstrated in ultraluminous disks, which emit very strong radiation.
Using a large-scale radiation electromagnetic hydrodynamics simulation based on general relativity, the researchers showed that the tilt and spin of a black hole cause its accretion disk to wobble like a spinning top.
This wobbling also causes the direction of the jets and radiation emitted by the black hole to change periodically.
The discovery suggests that the periodic changes in brightness of ultraluminous accretion disks, which have puzzled scientists for years, may be linked to the spin of the black hole.
The findings, published in The Astrophysical Journal, are a significant step forward in understanding how black holes influence their surroundings.
The researchers plan to continue studying this phenomenon by comparing long-term simulations with observational data to confirm whether black holes are indeed spinning.
This research is expected to greatly enhance our understanding of black hole behavior and contribute to our knowledge of the spacetime framework predicted by general relativity.
Source: University of Tsukuba.
