This simulation reveals what really happens near black holes
Black holes are among the most extreme objects in the universe, and now scientists can model them more accurately than ever before. By combining Einstein’s gravity with realistic behavior of light and matter, researchers have built simulations that closely match real astronomical observations. These models reveal how matter forms chaotic, glowing disks and launches powerful outflows as it falls into black holes. It’s a major step toward decoding how these cosmic engines actually work.
After decades of steady progress, computational astrophysicists have reached a major turning point in black hole research. A new study presents the most detailed and complete model yet of luminous black hole accretion, the process by which black holes pull in surrounding matter and emit intense radiation. Using some of the most powerful supercomputers on Earth, the researchers successfully calculated how matter flows into black holes while fully accounting for both Einstein's theory of gravity and the dominant role of radiation, without relying on simplifying shortcuts.
This achievement marks the first time such calculations have been carried out in full general relativity under radiation-dominated conditions. The results open a new window into how black holes behave in extreme environments that were previously out of reach for simulations.
Who Led the Research and Where It Was Published
The study was published in The Astrophysical Journal and led by scientists from the Institute for Advanced Study and the Flatiron Institute's Center for Computational Astrophysics. It represents the first paper in a planned series that will introduce the team's new computational framework and apply it to different types of black hole systems.
"This is the first time we've been able to see what happens when the most important physical processes in black hole accretion are included accurately. These systems are extremely nonlinear -- any over-simplifying assumption can completely change the outcome. What's most exciting is that our simulations now reproduce remarkably consistent behaviors across black hole systems seen in the sky, from ultraluminous X-ray sources to X-ray binaries. In a sense, we've managed to 'observe' these systems not through a telescope, but through a computer," said lead author Lizhong Zhang.
Zhang is a joint postdoctoral research fellow at the Institute for Advanced Study's School of Natural Sciences and the Flatiron Institute's Center for Computational Astrophysics. He began the project during his first year at IAS (2023-24) and continued the work at Flatiron.
Why Black Hole Models Need Relativity and Radiation
Any realistic model of a black hole must include general relativity, since the intense gravity of these objects bends space and time in extreme ways. But gravity alone is not enough. When large amounts of matter fall toward a black hole, enormous energy is released in the form of radiation. Accurately tracking how that radiation moves through curved spacetime and interacts with nearby gas is essential for understanding what astronomers actually observe.
Until now, simulations could not fully handle this combination of effects. Like simplified classroom models that capture only part of a real system, earlier approaches relied on assumptions that made the calculations manageable but incomplete.