A New X-Ray Spectro-Temporal Analysis Method and Its Application to the Suzaku MCG -6-30-15 Data

Abstract

A new X-ray spectro-temporal data-analysis method, which we call "the difference variation function method", is introduced. It can analyze spectral and temporal variations of X-ray sources, and its merits are discussed in comparison with conventional data-analysis methods. The new method is being applied to Suzaku observation data of the Seyfert 1 galaxy MCG $-$ 6-30-15. Consequently, it has been found that the observed spectral and temporal variations on a time scale of $\approx$ 10-100 ks are mostly ascribed to variable partially absorbers in front of the central X-ray source, whereas the X-ray source is intrinsically variable mainly on time scales shorter than $\approx$ 10 ks.