Hydrodynamics of circumbinary accretion: Angular momentum transfer and binary orbital evolution

Understand

We carry out 2D viscous hydrodynamical simulations of circumbinary accretion using the AREPO code.

• We self-consistently compute the accretion flow over a wide range of spatial scales, from the circumbinary disk (CBD) far from the central binary, through accretion streamers, to the disks around individual binary components, resolving the flow down to 2% of the binary separation.
• We focus on equal-mass binaries with arbitrary eccentricities.
• We evolve the flow over long (viscous) timescales until a quasi-steady is reached, in which the mass supply rate at large distances $\dot{M}_0$ (assumed constant) equals the time-averaged mass transfer rate across the disk and the total mass accretion rate onto the binary components.