The hydrodynamic evolution of binary black holes embedded within the vertically stratified disks of active galactic nuclei

Understand

Stellar-mass black holes can become embedded within the gaseous disks of active galactic nuclei (AGNs).

• Afterwards, their interactions are mediated by their gaseous surroundings.
• In this work, we study the evolution of stellar-mass binary black holes (BBHs) embedded within AGN disks using a combination of three-dimensional hydrodynamic simulations and analytic methods, focusing on environments in which the AGN disk scale height $H$ is $\gtrsim$ the BBH sphere of influence.
• We model the local surroundings of the embedded BBHs using a wind tunnel formalism and characterize different accretion regimes based on the local properties of the disk, which range from wind-dominated to quasi-spherical.