Top panel: phase-integrated polarization degree and angle in the 2.0–7.5 keV detected by DU 1 (blue), 2 (orange), and 3 (green), together with the sum of the three DUs (red). Middle panel: phase-integrated polarization degree and angle in the 2.0–4.0 keV (blue) and in the 4.0–7.5 keV (orange) energy intervals. Bottom panel: phase-integrated polarization degree and angle in the 2.0–7.5 keV band relative to the warm BB (cyan) and to the hot BB (yellow) components. The filled and empty contours mark the 68% and 99% confidence intervals, respectively.