Stochastic Resonance of a General Relativistic Accretion Disk

Based on a generalized Langevin equation, we consider a full general relativistic model to describe the vertical oscillations of particles in accretion disks around compact astrophysical objects, and calculate oscillating luminosity and power spectral density (PSD) of an accretion disk. The influences of the friction parameter ζ, spin parameter a_? and mass M of the center compact object on the stochastic resonance (SR) in PSD curves are discussed. The results show that a large spin parameter a_? can enhance the SR phenomenon, but the larger the ζ or M is, the weaker the SR phenomenon becomes. In addition, our simulated PSD curves of the output luminosity of stochastically oscillating disk have the same profile as the observed PSD of x-ray binaries, and the resonance peak in the PSD curve can interpret the quasi-periodic oscillations at the same time.