Models from tpho for component 5 in the 15 − 18 Å binned with 0.1 Å. Panel a shows the transmission of component 5 in the high-flux state (blue) and low-flux state (red) and the transmission ratio (black) from the low-flux state over the high-flux state. Panel b shows the transmission ratio of component 5 as a function of increasing density. Panel c shows the observed ratio (black) was fitted well by the tpho model with a density of 10^13.4 m⁻³ including the O VII RRC feature (red). The local scaling factor of 2.21 was calculated from the counts in the 9 − 14 Å range.