Effect of absorption on a power law spectrum of Γ = 1.7 and Galactic absorption of N_H = 3 × 10²⁰ cm^-2 here adopting the effective area of XMM. Absorbers with various ionisation parameters have been tuned such that the soft (0.2–2 keV) X-ray flux is reduced by a factor ten. The necessary column densities are 0.89 × 10²² cm^-2 for the neutral absorber, 0.67 × 10²² cm^-2 for low ionisation (log (ξ) = −1), 2.26 × 10²² cm^-2 for medium ionisation (log (ξ) = 0.5) and 36.1 × 10²² cm^-2 for high ionisation (log (ξ) = 2).