Top left panel: measured spectral energy distribution of IC 310 in the X-ray band in different time periods; Chandra Obs. ID 5596 (green), XMM-Newton (blue), Chandra Obs. ID 5597 (red) and Swift-XRT (orange). The solid lines show the absorbed power-law fit and the dashed lines show the de-absorbed fit, respectively. Bottom left panel: residuals of the χ² fit. Right panel: contour plot between the intrinsic column density N_H and the X-ray photon index Γ for the spectra depicted in the left panel. The contours for each observation are given at 68%, 90%, and 99% confidence levels. For comparison, the Galactic N_H value is 0.12 × 10²² cm^-2.