Accretion discs 1 Accretion, accretion disks 1 Accretion: accretion disks 1 Black holes 1 Galaxies 1 Galaxies active 1 Galaxies: active 1 Gravitation 1 ISM jets and outflows 1 ISM: jets and outflows 1 Jet instability Lower frequencies 1 Magnetohydrodynamic 1 Magnetohydrodynamics 1 Magnetohydrodynamics (MHD) 1 Oscillators (mechanical) 1 Quasiperiodic oscillations 1 Stability 1 Stars 1 X-rays: Binaries 1 X-rays: binaries 1