Black Holes Eat Up Their Environment at a Much Faster Rate Than Previously Believed

Saturday - September 23 2023, 00:50 UTC - 1 year ago

A study conducted by researchers from Northwestern University discovered that black holes can consume their surroundings much faster than what classical disk theory suggests. By using 3D simulations run on Summit — one of the world’s largest supercomputers — the team found that black holes rip through their accretion disk, ingesting it in a matter of million or billion years. This new insight could greatly improve our understanding of the environment of black holes.

New research by Northwestern University has revealed that black holes eat up their surrounding environment much faster than previously believed.Black holes' interaction with neighboring matter is often referred to as "eating". While black holes don't consume food like living beings, their immense gravitational pull enables them to attract nearby objects such as gas, dust, and even other stars .

Classical accretion disk theory expects slow disk evolution, taking millions and billions of years for the disk to form and for the material to be ingested by the black hole. But the new study, according to a press release, used 3D simulations to discover that the massive celestial objects rip through their accretion disk, essentially consuming it at dizzying speeds.An accretion disk refers to a swirling disk of matter spiraling into a black hole that occurs when the object is in a binary system with a companion star or when it is surrounded by a cloud of gas and dust .

These elements are attracted to the black hole by its strong gravitational pull.Some of this matter might fall directly into the black hole and become ingested, while other pieces might be expelled as high-energy jets along the rotational axis of the black hole."Classical accretion disk theory predicts that the disk evolves slowly," said Nick Kaaz, graduate student in astronomy at Northwestern who led the study .

"But some quasars — which result from black holes eating gas from their accretion disks — appear to drastically change over time scales of months to years. This variation is so drastic. It looks like the inner part of the disk — where most of the light comes from — gets destroyed and then replenished. Classical accretion disk theory cannot explain this drastic variation. But the phenomena we see in our simulations potentially could explain this .

The quick brightening and dimming are consistent with the inner regions of the disk being destroyed," Kaaz continued.A supermassive black hole, which typically has a mass between millions and billions of times that of the Sun, resides at the center of every quasar. Furthermore, a massive quantity of energy is released as matter enters the black hole and creates an accretion disk.The researchers ran a 3D simulation of a thin, tilted accretion disk using general relativistic magnetohydrodynamics (GRMHD) on Summit, one of the largest supercomputers in the world housed at Oak Ridge National Laboratory .

Previous simulations lacked the power to incorporate all the physics required to build a realistic black hole, but the model developed by Northwestern combines general relativity, magnetic fields, and gas dynamics to provide a more complete image.Their observations of changing-look quasars showed that accretion disks evolve much, much quicker than the assumptions made by classical theory. In addition to possibly explaining quasars, the new simulations may also provide new insight into the mystifying properties of black holes .

"How gas gets to a black hole to feed it is the central question in accretion-disk physics," Kaaz said. "If you know how that happens, it will tell you how long the disk lasts, how bright it is and what the light should look like when we observe it."The new results provide a much greater understanding of how material from the host galaxy falls into the black hole and of the extreme environment that surrounds the object .