We present results from analysis of the X-ray archive data of MCG - 2-58-22 , acquired with ROSAT from 1991 to 1993 and with ASCA from 1993 to 1997 .
By analyzing light curves , we find that MCG - 2-58-22 shows a clear time variability in X-ray flux .
The time scales of the variations range widely from \sim 10 ^ { 3 } s to more than years .
Among the variations , a flare-like event overlaid on the gradual flux decrease from 1979 to 1993 is detected in the 1991 data ; the flux has increased at least by a factor of 3 .
Combined analysis of the ROSAT and ASCA spectra shows that a simple absorbed power-law does not fit the overall energy spectra , unless the column density lower than the Galactic value ( 3.5 \times 10 ^ { 20 } cm ^ { -2 } ) is adopted .
We find the clear time variability of the spectra in the energy range of 0.1–2.0 keV .
The spectral shape with respect to an adopted model continuum is generally correlated with their flux level .
However , the flux variation does not result in any significant influences on their spectra in the energy range of 2–10 keV .
As reported previously , there is an iron line centered at \sim 6.3 keV ( which is not corrected for the red-shift effect ) , but we find that the line width is broad \sigma = 0.9 ^ { +0.6 } _ { -0.3 } keV with a single Gaussian model .
The implications of these observational results are discussed in terms of a supermassive black hole model and accretion flow dynamics near the central black hole .