Contour plots of N_H (10²⁶ m⁻¹) against N_pow (10⁵⁰ ph s⁻¹ keV⁻¹; top panels) and N_H (10²⁶ m⁻¹) against N_comt (10⁵³ ph s⁻¹ keV⁻¹; bottom panels). From left to right, the panels show the contours for the time-averaged model, TB2, TB6, and TB9, respectively, in Obs 1. The levels of confidence presented are at 68 % (ΔC = 2.30; black solid line), 90 % (ΔC = 4.61; red dashed line), and 95 % (ΔC = 6.17; blue dotted line). The black crosses show the parameter values (but not the errors) from the best fit models in Table 3.