Left: Slope of a power-law model absorbed by the Galactic column fitted to the X-ray spectra of XMMSL2 J1404-2511. Red points are from XMM-Newton, blue points from Swift-XRT. Middle: Temperature (eV) of a simple model of a black-body absorbed by the Galactic column of N_H = 6.7 × 10²⁰ cm⁻² fitted to the X-ray spectra of XMMSL2 J1404-2511. Note that this does not represent the physical temperature of the disc but illustrates how the spectrum hardens with time. Right: Optical depth of a 5 keV electron population derived from fits of a COMPBB model, absorbed by the Galactic column, to X-ray spectra of XMMSL2 J1404-2511 from 2018 and 2019.