Comparison between the F_var spectrum of the 2007 and 2019 data. The 2019 observations (magenta) were obtained by grouping together the five exposures via the standard command SETPLOTGROUP within XSPEC. The spectrum derived from 2007 data is in black. The magenta curve represents a theoretical F_var spectrum, which depicts the combined contribution from a variable power-law-like continuum and a variable soft excess.