Abstract
We numerically study the formation of gaps in circumbinary disks of comparable mass massive black hole binaries (q ∼ 1). We vary the disk properties (mass, thermodynamics, etc.) and found that most massive and thicker disks are able to prevent the gap formation in them. We contrast our results against analytical models based on the non-axisymetric perturbation enhanced in the disk, which succesfully predicts the disks that opens a gap. We discuss the implications for the occurence of opened and failed gaps in the final separations and posible merging of binary AGNs.
