Synthetic observables from a line of sight oriented vertically to the solar surface at t = 4414 s in the simulation. Panel a displays the Hα wing radiation at the Hα −0.5 Å wavelength calculated by using the RH1.5D code. Panel b shows the Si IV 139.4 nm synthetic radiation image calculated by using the optically thin method. Panel c presents the synthetic image of the EUI 17.4 nm band, also calculated by using the optically thin method. Hereafter, I_R denotes the relative radiation intensity.