ArXiv · 2026
We study the dynamical response of a hydrodynamic disk to an impulsive kick imparted to a central massive object, focusing on the global properties of the material that remains gravitationally bound. We construct a simple analytic model and show that the bound material can acquire a significant tilt—or even a retrograde rotation—if the kick is directed close to the disk midplane. We perform 3D numerical simulations and show that (1) the bound material relaxes to a torus-like circularized flow of which total mass and angular momentum is in fair agreement with the analytic estimate, and (2) in spite of nonlinear hydrodynamic effects, a highly tilted or retrograde disk can be sufficiently formed. The simulations additionally reveal a transient warp in the kicked disk, suggesting a kick as a formation mechanism of tilted or warped disks around compact objects. About 10% of the kinetic energy the bound material acquired from the kick is converted to the internal energy, while the exact conversion efficiency depends on the kick angle and the initial surface mass density profile. The luminosity of this kick-driven dissipation flare can reach ∼ 10⁴³ rm erg s⁻¹ for strong kicks (V_(rm kick) ∼ 1000km/s). We discuss the implications of our results for recoiling supermassive black holes, recoiled stellar-mass black holes in the disks of active galactic nuclei, and natal kicks on compact objects.
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