“…Spectral studies of warm absorbers highlight their complex multiphase structure, which spans a wide range of ionisation parameters, log(ξ/erg cm s −1 ) = −1 to 3, and column densities, N H = 10 21−23 cm −2 (Blustin et al 2005;McKernan et al 2007;Krongold et al 2009;Tombesi et al 2013;Laha et al 2014;Behar et al 2017). They are usually detected as absorption lines and edges from H-like and He-like ions of the most abundant elements, such as C, O, N, Ne, Mg, Si, Si and Fe, in the soft spectra below 2 keV (Crenshaw et al 2003;Mehdipour et al 2010Mehdipour et al , 2018Ebrero et al 2021). Low ionisation absorbers (log ξ = 0 − 1.5) imprint deep spectral absorption troughs in the rest frame wavelength 15−17 Å due to the blended Fe M shell unresolved transitions array (UTA; Behar et al 2001).…”