Studying the unique properties of black holes is of great interest. As the black holes don’t allow escape of light, they can’t be directly perceived by telescopes.
Accretion disks are one way to observe black holes indirectly. They emit light and other radiation that telescopes can detect. Accurately simulating accretion disks dramatically improves our understanding of the physical processes around black holes. It offers crucial insights for interpreting observational data from the Event Horizon Telescope.
Researchers at Tohoku University and Utsunomiya University have made a breakthrough in studying turbulence in accretion disks around black holes. They used advanced supercomputers to create the highest-resolution simulations ever.
Researchers used supercomputers such as RIKENs Fugaku and NAOJs ATERUI II to perform unprecedentedly high-resolution simulations.
Previous simulations of accretion disks couldn’t capture the “inertial range” due to limited computing power. This study is the first to successfully reproduce this range, connecting large and small turbulence eddies in accretion disks.
The study also found that “slow magnetosonic waves” dominate the inertial range. This helps explain why ions in accretion disks get heated selectively. The turbulence in the electromagnetic fields can interact with charged particles, possibly accelerating some to very high energies.
In magnetohydrodynamics, the main types of waves are magnetosonic waves (slow and fast) and Alfvén waves. The study found that slow magnetosonic waves dominate the inertial range, carrying about twice as much energy as Alfvén waves. This contrasts with solar wind turbulence, where Alfvén waves are more dominant.
This discovery should enhance the interpretation of observational data from radio telescopes studying areas near black holes.
Journal Reference:
- Yohei Kawazura et al., Inertial range of magnetorotational turbulence, Science Advances (2024). DOI: 10.1126/sciadv.adp4965