XMM-Newton EPIC spectra and the corresponding best-fit models focused on the Fe K band. Top: unfolded EPIC-pn (black), EPIC-MOS 1 (dashed red), and EPIC-MOS 2 (dashed green) spectra, between 5–10 keV, of the eight observations where the Fe K absorption line was detected at P_ℳ𝒞 ≳ 95%. The spectra were firstly unfolded against a power law of Γ = 2, and their corresponding best-fitting model (solid red) was overlaid afterwards. Middle: corresponding EPIC data counts and best-fitting model. Bottom: data/model ratio. The presumed absorption features at ∼ 9.2 keV and ∼ 9.5 keV present in, for example, 2MASSJ105144+3539 and 2MASS J165315+2349, respectively, are simply not significant enough to be considered as detections (see Figs. 4 and E.1), and hence they were not included in the best-fitting models.