Determine the prevalence of thin, thick, and asymmetric AGN disk structures

Determine how commonly thin disks, puffed-out thick disks, or asymmetric disk structures arise for the AGN parameters modeled in the radiation magnetohydrodynamic simulations.

Background

The simulations develop a thin upper disk and a substantially thicker lower disk through stochastic turbulent evolution. The paper emphasizes that this asymmetry results from the particular realization of fluctuations in the initial gray simulation and may not be representative of all disks with the same supermassive black hole mass and accretion rate.

Establishing the prevalence of these alternative disk structures requires simulations with additional stochastic realizations and a broader exploration of AGN parameters. This matters because the disk geometry strongly affects X-ray absorption, intrinsic UV-optical variability, reverberation-mapping lags, and the possibility of inferring disk thickness from observed light curves.

References

Because the turbulent fluctuations leading to this difference between the top and bottom of the disk are stochastic, there is no guarantee that this precise disk structure would arise, and we cannot predict how common a thin or thick disk or an asymmetric disk would be based on this one initial simulation.

— Disk Structure May Determine AGN Variability and Explain the Accretion Disk Size Problem: No Broad Line Region Required  (2610.12462 - Secunda et al., 8 Oct 2026) in Section 3, “Disk Properties”