Examples of line profiles and their evolution across the UVES spectra. Each subpanel is for a different transition (specified in the subpanel title); early epochs are on top, and later ones in the bottom of each subpanel. The vertical shaded area marks the velocity range (−200, −115) km s⁻¹ where the persistent absorption is located. Velocities are in the heliocentric rest frame. Y-axis units are in erg cm⁻² s⁻¹ Å⁻¹.