Gravitational Waves Produced by Ejection of Jet Superluminal Components, Precession and Gravito-Magnetic Distortion of Accretion Disks in Active Galactic Nuclei, Micro-Quasars, and T-Tauri Stars Dynamically Driven by Bardeen-Petterson Effect

摘要

Jet superluminal components are recurrently ejected from active galactic nuclei, micro-quasars, T-Tauri star,and several other astrophysical systems. The mechanism driving this powerful phenomenon is not properly settled downyet. In this article we suggest that ejection of ultrarelativistic components may be associated to the superposition of twoactions: precession of the accretion disk induced by the Kerr black hole (KBH) spin, and fragmentation of tilted disk; thislast being an astrophysical phenomenon driven by the general relativistic Bardeen-Petterson (B-P) effect. Asfragmentation of the accretion disk takes place at the B-P transition radius, a suspended accretion state can develop amidthis boundary and the innermost stable orbit around the KBH, which drives a turbulent flow along the inner accretion disk.The torus distortion caused by both hydrodynamic coupling of the inner face to the outer face, and Maxwell stresses fromthe magnetic field makes it to generate gravitational waves from its turbulent flow in the suspended accretion state. Thismagneto-centrifugal barrier also precludes incoming matter to penetrate the inner disk, creating ``en passant'' a sort offorce-free region. The incoming material trapped in this sort of Lagrange internal point will forcibly precess becoming asource of continuous, frequency-modulated gravitational waves. Eventually, a condition of orbital resonance (beating) canactivate between the precession pace and the frequency of the warps travelling along the torus due to its differentialrotation. As this transition radius behaves like a sort of Lagrange internal point in a force-free magnetosphere, atresonance blobs can be expelled at ultrarelativistic velocities from the B-P radius in virtue of the power provided by eitherthe vertical (to the disk) linear momentum carried by the surface acoustic wave on the torus warps, or the Aschenbacheffect in a nearly maximal KBH, or some other orbital resonance like the well known resonance 3:1. The launching ofsuperluminal components of jets should produce powerful gravitational wave (GW) bursts during its early accelerationphase, which can be catched on the fly by current GW observatories. Here we compute the characteristic amplitude andfrequency of such signals and show that they are potentially detectable by the GW observatory LISA.