Light curves in different energy ranges. On the x-axis, we report the last three digits of the Modified Julian Date. On the y-axis, on both left and right side, we report the count-rate. Black circles: XMM-Newton (0.3–0.5 keV, 0.5–2 keV, 2–10 keV); magenta nablas: Chandra (0.5–2 keV, 2–10 keV); red squares: NuSTAR (20–40 keV, 40–80 keV); blue triangles: INTEGRAL (20–40 keV, 40–80 keV, 80–300 keV). The vertical dotted lines highlight the seven observations we analysed in this paper (i.e., those including NuSTAR and/or INTEGRAL data).