Hard X-ray light curve and Chandra spectrum during obs-2. Top panel: INTEGRAL light curve. The dashed vertical lines indicates the boundaries of the 3.2 ks spectra (also used in K15). Following the hard X-ray evolution, we have divided the observation into three intervals: obs-2.A (spectra 1–4; low flux), obs-2.B (5–7; plateau), and obs-2.C (8–9; flares). Bottom panel: combined MEG+HEG spectrum. We have labelled the emission lines included in this analysis (see Sect. 3).