Disc Novae: Thermodynamics of Gas Assisted Binary Black Hole Formation in AGN Discs

Understand

We investigate the thermodynamics of close encounters between stellar mass black holes (BHs) in the gaseous discs of active galactic nuclei (AGN), during which binary black holes (BBHs) may form.

• We consider a suite of 2D viscous hydrodynamical simulations within a shearing box prescription using the Eulerian grid code Athena++.
• We study formation scenarios where the fluid is either an isothermal gas or an adiabatic mixture of gas and radiation in local thermal equilibrium.
• We include the effects of viscous and shock heating, as well as optically thick cooling.