Hardness ratio of the 55 ks and 150 ks Suzaku observations Suz 2 (top) and Suz 3 (bottom) given by the ratio of count-rate light curves extracted between 6–10 keV and 2–5 keV. The shaded regions divide the observation in different parts for a time-resolved spectroscopy and are derived using a Bayesian block analysis. The green-shaded and striped region in the bottom panel indicates the relative observation time of Nu_Suz.