Isolate the cause of the weakened sep15M outflow

Determine whether the weakened outflow in the sep15M continuation is caused primarily by the changing primary-black-hole spin direction, the evolving orbital plane, or the redistribution of gas between the two black holes.

Background

Near the end of the sep15M continuation, the primary-spin component normal to the circumbinary disk has crossed back to positive values, the orbital plane is beginning to tilt away from the disk, and gas is being redistributed between the two black holes. Because these effects evolve simultaneously during the short continuation, the simulation cannot assign the weakened jet structure to any single mechanism.

References

Because all three evolve simultaneously during this short continuation, the sep15M run cannot isolate any one of them as the sole cause of the weakened outflow.

— Jet variability in small mass ratio supermassive black hole binaries  (2609.24837 - Kalinani et al., 21 Sep 2026) in Appendix, Section “The sep15M run”