Supermassive black holes are one of the most extreme phenomena discovered by humans in outer space. With hundreds of thousands, even millions to billions of times the mass of our Sun, they power unprecedented luminous phenomena called quasars.
Researchers at Northwestern University used the Summit supercomputer to conduct a "three-dimensional general relativistic magnetohydrodynamics" simulation of a tilted thin accretion disk orbiting a supermassive black hole. Thanks to Oak Ridge National Laboratory's powerful high-performance computing systems, scientists are able to simulate more realistic black holes than ever before and discover new phenomena in the process.
The researchers noted that conventional theories about supermassive black holes hold that they are celestial entities that gradually devour gas and dust over hundreds or even hundreds of thousands of years. However, according to new simulations, this depletion process appears to occur in just a few months, coinciding with the time required for active quasar launches.
Three-dimensional simulations produced by Northwestern University scientists illustrate that a spinning black hole distorts the surrounding region of space-time. This phenomenon eventually tears apart the swirl of gas and dust surrounding the black hole, known as the accretion disk. The end result of this space-time warping process is to split the accretion disk into two sub-disks, an inner one and an inner one, which subsequently fuels the ultrafast feeding behavior described in the new study.
Researchers say a singularity at the center of a black hole initially engulfs the inner ring. Subsequently, fragments of the outer disk spilled inward, filling the gap left by the devouring of the inner ring, allowing the devouring process to repeat. Scientists point out that this endless process of "eating" - "eating" - "eating" again only takes a few months. This timescale is incredibly fast compared to previous theoretical predictions.
This new simulation can reveal the behavior of some of the brightest objects observed in the universe, such as quasars. These quasi-stellar objects can be as bright as all the stars in their host galaxy combined, but disappear "without explanation" after a few months. Nick Kaaz, who led the study at Northwestern University, pointed out that classical accretion disk theory predicts that the disk around the black hole will evolve very slowly.
However, Katz explained that some quasars experience more dramatic changes in brightness over months or years. The rapid fluctuations in brightness observed in quasars are consistent with the observation of multilayered disks and their complex physical interactions through new simulations of black holes.