The combined RXTE/PCA, RXTE/HEXTE and Swift/BAT data from MJD 53384 (53384a in Table 4) fitted simultaneously with a simple power-law model. The data have been rebinned to 5σ for the plot only. Top panel: counts spectrum with residuals, the PCA, HEXTE and BAT points are indicated by crosses, circles and squares, respectively. Bottom panel: unfolded energy spectrum. The offset in normalization between the BAT and HEXTE data is surprising and indicates the need for a careful study of spectral fits with the BAT survey data in relation to other instruments. Such a study is beyond the scope of this paper but the discrepancy does not affect the results presented here.