Computer simulations lead astronomers to believe that black holes may have surrounding black hole fountains.
Theoretical physicist Stephen Hawking, who died in March, guest-starred in several TV series, including The Simpsons.
In Hawking’s first appearance on the show, Homer and professor Hawking are drinking buddies who share their big thoughts on the Universe.
Of course, Homer believes the Universe has a donut shape. Hawking then becomes so intrigued about the idea that he allegedly steals it.
The idea that the Universe is shaped like a donut has its roots in science.
In a donut-shaped Universe, space is finite and “wrap-around”. If you keep going straight in one direction, you arrive from the opposite direction.
Earth is also at the center of large donut-shaped forcefield, or what NASA calls a plasmasphere.
If “donut” is one of the possible shapes of the Universe, it’s also believed to be the case with black holes.
But we may have to rewrite textbooks to correct what we got wrong about black holes’ shape and the behavior of matter around them. Now, researchers believe that there may be black hole fountains surrounding the cosmic giants.
Black Hole “Donuts” are Dynamic Black Hole Fountains
Black holes, the gargantuan monsters that roam the cosmos swallowing stars, never stop surprising us.
While modern astrophysics has piled up a substantial knowledge about them, there are many layers of mystery to the nature of black holes.
One of the first questions about black holes, which puzzles scientists and interests ordinary people, is what do black holes really look like?
Take accretion disks, for example, which surround black holes. These disks are reportedly formed by gaseous matter.
Astrophysicists have long assumed that the gas rings around black holes take a rigid donut-shaped structure.
Recent observations and computer simulations conducted by physicists at the National Astronomical Observatory of Japan (NAOJ), however, suggest that the matter swirling around black holes doesn’t behave the way we thought.
Instead of taking on a donut structure, gas rings surrounding active black holes behave like “dynamic water fountains”.
Read More: Soft Hair on Black Holes: Stephen Hawking’s Last Scientific Paper
“Previous theoretical models set a priori assumptions of rigid donuts. Rather than starting from assumptions, our simulation started from the physical equations and showed for the first time that the gas circulation naturally forms a donut. Our simulation can also explain various observational features of the system,” explains Keiichi Wada, who lead the research.
NAOJ researchers used the Atacama Large Millimeter/submillimetre Array (ALMA) to observe a supermassive black hole about 14 million light-years away.
They then ran computer models to simulate how gas falls toward a black hole on NAOJ’s supercomputer (Cray XC30 ATERUI).
Their findings suggest that the presumptive donut shape is not actually a rigid structure “but instead a complex collection of highly dynamic gaseous components.”
First, falling cold gas forms a disk near the black hole’s plane of rotation. As the heat rises approaching the black hole, gas molecules break down. Then, hot gas atoms are expelled from the center and fall back down. This creates a tumultuous 3D fountain-like structure.
Now, that doesn’t really rule out the donut-shape. However, it does question its “rigidity” and reveals the dynamism of gaseous matter that led scientists to believe in the “donut” in the first place.
“By investigating the motion and distribution of both the cold molecular gas and warm atomic gas with ALMA, we demonstrated the origin of the so-called ‘donut’ structure around active black holes.”
Previous NASA observations revealed that matter rotating around supermassive black holes form a clumpy doughnut that doesn’t feature rounded contours.
Could the Center of that fountain contain a stream of recently converted dark matter.