Understand
Many astrophysical binaries, from planets to black holes, exert strong torques on their circumbinary accretion disks, and are expected to significantly modify the disk structure.
- Despite the several decade long history of the subject, the joint evolution of the binary + disk system has not been modeled with self-consistent assumptions for arbitrary mass ratios and accretion rates.
- Here we solve the coupled binary-disk evolution equations analytically in the strongly perturbed limit, treating the azimuthally-averaged angular momentum exchange between the disk and the binary and the modifications to the density, scale-height, and viscosity self-consistently, including viscous and tidal heating, diffusion limited cooling, radiation pressure, and the orbital decay of the binary.
- We find a solution with a central cavity and a migration rate similar to those previously obtained for Type-II migration, applicable for large masses and binary separations, and near-equal mass ratios.