GRAVITATIONAL WAVES FROM EJECTION OF JET SUPERLUMINAL COMPONENTS AND PRECESSION OF ACCRETION DISKS DYNAMICALLY DRIVEN BY BARDEEN-PETTERSON EFFECT

Abstract

Jet superluminal components are recurrently ejected from active galactic nuclei, micro-quasars, T-Tauri star, and several other astrophysical systems, including gamma-ray burst sources. The mechanism driving this powerful phenomenon is not properly settled down yet. In this article we suggest that ejection of ultrarelativistic components may be associated to the superposition of two actions: precession of the accretion disk induced by the Kerr black hole (KBH) spin, and fragmentation of the tilted disk; this last being an astrophysical phenomenon driven by the general relativistic Bardeen-Petterson (B-P) effect. As fragmentation of the accretion disk takes place at the B-P transition radius, the incoming material that get trapped in this sort of Lagrange internal point will forcibly precess becoming a source of continuous, frequency-modulated gravitational waves. At resonance blobs can be expelled at ultrarelativistic velocities from the B-P radius. The launching of superluminal components of jets should produce powerful gravitational wave (GW) bursts during its early acceleration phase, which can be catched on the fly by current GW observatories. Here we compute the characteristic amplitude and frequency of such signals and show that they are potentially detectable by the GW observatory LISA.