second component in Mg [ii]{} is reached for any given pixel. Figure \[fig:condensation\] displays the resulting curves. For each time step (given by the cadence of the observations, 9.4s) the number of pixels within a 2 km/s interval is represented by the gray scale. The bar in the figure gives the number of pixels within each time-velocity bin.

![Superposed epoch analysis of chromospheric condensation flows derived from the second component of the IRIS lines’ fits. The velocity curve for each pixel is aligned in time to the occurrence of maximum centroid shift for the second component of Mg [ii]{} at that pixel. The velocity indicates down-flow motions and the strength of the colortable dictates the number of instances within a 2 km/s velocity interval for each time step.[]{data-label="fig:condensation"}](vcurves_cen_may22.eps){width="9cm"}

From Figure \[fig:condensation\] we can immediately confirm that the behaviour described in Sect. \[sec:chrom\_spectra\] is common to the majority of the flaring pixels in the ribbon sampled by the IRIS slit. While clearest for the Mg [ii]{} line, the evolution of the red-shifted component for all considered pixels and spectral lines falls within a fairly narrow envelope, starting at a maximum redshift of up to 50 km s$^{-1}$, and rapidly decaying to 