Original title: Magnetized accretion onto rapidly spinning binary black holes: mini-disk thermodynamics, magnetic transport, and dual jets
Luciano Combi, Manuela Campanelli, Sean M. Ressler, Alexander J. Dittmann +1 · September 2026
Supermassive black holes sometimes orbit each other in pairs inside dense clouds of gas. Finding them is hard because ordinary gas clouds flicker randomly. Scientists need clear signatures that prove two black holes are actually orbiting together. To investigate this, researchers ran detailed computer simulations of two equal-mass black holes spinning rapidly with spin χ=0.9 and separated by 30 gravitational radii. The pair feeds on a large shared disk of magnetized gas. Each black hole forms its own smaller mini-disk of matter. Gas sloshes between these mini-disks, while magnetic fields funnel energy outward to launch twin jets with an energy extraction efficiency near ≈ 40%. Crucially, the magnetic power and brightness flip back and forth between the two black holes, creating an on-off dual-jet pattern. When the mini-disks stay hotter, they hold less mass, produce weaker periodic signals, and power dimmer jets.
Imagine two people sharing a single bicycle. When one rides, the other must wait, and their turns are unpredictable due to how fast the first one goes. Here, the two black holes take turns launching jets as they draw gas from a shared disk, with the strength of each jet depending on how much magnetic field reaches it.
This helps astronomers predict binary black hole signatures in gravitational wave searches. It shows how jet alternation might reveal their presence, improving multi-messenger astronomy.
The study is limited to equal-mass binaries with high spin and a separation of 30 gravitational radii; it may not generalize to other configurations. The simulations assume specific cooling models for mini-disks.
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Magnetized accretion onto rapidly spinning binary black holes: mini-disk thermodynamics, magnetic transport, and dual jets — Luciano Combi, Manuela Campanelli, Sean M. Ressler et al.
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.