Relativistic Patchwork Disks around a Schwarzschild Black Hole: Light Curves and Spectrum

We have calculated the observed flux from a relativistic accretion disk rotating around a Schwarzschild black hole. The disk is hypothesized to be patchworked by a non-radial wave pattern that propagates in the azimuthal direction. The surface emperature of a patchworked region was set to be slightly high in some regions and low in other regions. Due to the Doppler effect and gravitational lensing, the observed flux changes during the propagation of wave patterns. As a result, the light curves of such a patchwork disk change. We found that the amplitude of the light curves becomes of the order of 10%, in spite of the fact that the amplitude of the surface temperature is 5%. The light curves are asymmetric due to the relativistic effect. The spectra of this type of a patchwork disk were also calculated. As expected, the spectra become hard in the bright phase and soft in the dark phase