The disc luminosity in HLX-1. Left: the shaded areas indicate the 90% confidence interval for the luminosity distribution associated with the black hole mass measured in Fig. 3. Again, the the result for a_∗ = 0.5 is singled out and given by the three solid lines (with 90% confidence), corresponding, respectively, to the Chandra (grey), Swift (green) and XMM (blue) spectrum. Right: the influence of the black hole spin on the luminosity of the Swift spectrum. Error bars give the 90% confidence interval.