Data/model ratio plots of the PCA/HEXTE/PIN data added to the best-fit model fitted between 4−10 keV with the XMM-Newton and Suzaku data (Tables 3 and 4). The PCA/HEXTE/PIN data are allowed a free constant, but all other parameters are frozen to the values listed in Tables 3 and 4. Observations 1−3 show very good agreement with the hard X-ray data, suggesting that the model fit between 4−10 keV is correct. However, in Observation 4 there appears to be a large discrepancy between the pn and PCA data. Hard X-ray data are colour-coded as PCA (red), HEXTE (green) and PIN (blue), and fit in the energy ranges outlined in Sect. 2.