A leap forward in understanding the Universe. This is the promise of the new simulation developed by a team of astrophysicists led by Caltech. For the first time, this simulation traces the journey of primordial gas in the early Universe to its integration into an accretion disk feeding a supermassive black hole, thus overturning concepts established since the 1970s.
Image taken from the simulation showing a supermassive black hole surrounded by a rotating accretion disk.
Credit: Caltech/Phil Hopkins group
Under the direction of Phil Hopkins, a professor of theoretical physics, this technological feat required years of work and collaboration between two major projects: FIRE and STARFORGE. These projects focus on different scales, ranging from galaxy formation to that of individual stars, finally bridging a gap between these two phenomena.
With a resolution 1,000 times higher than that of previous simulations, researchers have discovered the predominant role of magnetic fields in the formation and structure of accretion disks around supermassive black holes. These fields, far from being anecdotal, play a central role in making these disks more "foamy" than expected.
The Open Journal of Astrophysics reports that these disks, initially assumed to be flat, are actually supported by magnetic pressure, which vastly exceeds the thermal pressure of the gas. This discovery challenges many assumptions about the mass, density, and dynamics of these disks.
Credit: California Institute of Technology The simulation uses a code called GIZMO, capable of handling both large cosmic scales and microscopic details. By modulating the different physical components, the researchers simulated a black hole 10 million times the mass of the Sun from the early Universe to the accretion of matter around this black hole.
This advancement opens new research perspectives: understanding in detail the merger of galaxies, star formation in dense regions, and the characteristics of the first generations of stars. The implications are vast, providing avenues to explore many still-mysterious cosmic phenomena.