Simplified stellar models like as one-zone models can be oscillated in chaotic state (Saitou et al. 1989). It is natural to consider that the irregular variations of Galactic X-ray sources might be caused from nonlinear oscillation of accretion disks or related flow. We studied the variability of Cen X-3 for applying the nonlinear theory to it.
The X-ray of Cen X-3 observed with Ginga from 22nd to 24th of March, 1989 are analyzed. Since Large Area Counters (LAC) of which the area of detector is 4,000 cm2 are used. The data used here is obtained the range of 1,000 sec from 14 h 25 m on March 23rd with the time resolution of 0.25 sec. The energy bands are 1.7~4.6 keV, 4.6~9.3 keV, 9.3~19 keV, and 19~37 keV, respectively.
Takeshima et al. (1991) show that Cen X-3 is at the high state, when the X-ray from the source is not veiled by non-ionized matter (Schreier et al. 1976). So that we ignore the effect of circumstellar matter around the source.