We report results from an analysis of the X-ray archival data on MCG-2-58-22 obtained with Ginga, ROSAT and ASCA. By analyzing both short- and long-term light curves, we find clear time variations, ranging widely from, ~10 3 s to more than several years, in the X-ray energy range 0.1 - 10 keV. In addition, a flare is detected in 1991, overlaid on a gradual, secular flux decrease from 1979 to 1993; this flare has a time scale of about 1 year, and the X-ray flux increased by at least a factor of 3. The implications of these observational results are discussed in terms of accretion flow dynamics near a supermassive black hole.

• CHUL-SUNG CHOI(Korea Astronomy Observatory)
• TADAYASU DOTANI(Institute of Space and Astronautical Science)
• INSU YI(School of Physics, Korea Institute for Advanced Study)
• ANDRE FLETCHER(Korea Astronomy Observatory)
• CHULHEE KIM(Department of Earth Science Education, Chonbuk National University)