Constraints on M_• and a_• from the slim disc model fit to the spectra obtained at all observing epochs. We calculate the ΔC-stat across the {M_•, a_•} plane with respect to the best–fit value (yellow marker) from Table D.1 (left) and from Table D.2 (right). Areas within the 1σ and 2σ confidence limits for two–parameter error estimates are shown in red and blue, respectively. Considering both scenarios, M_• is constrained to be (6 ± 3)×10⁴ M_⊙ at the 2σ level for the two-parameter fits. The lower limit on the black hole spin is constrained to be > 0.6 at the 2σ (97.8%) single–sided confidence level.