Scattering cross-section of H I Lyαλ1216, Si IIλ1190, Si IIλ1193, Si IIλ1260, C IIλ1334, Fe IIλ2586, Fe IIλ2600, Mg IIλ2796 and Mg IIλ2803. The core-wing transition, highlighted by the yellow stripe, occurs at |x|≈3 − 4, depending on the lines. The cross-sections have been computed using the atomic parameters listed in Table 1 assuming a Doppler parameter value of b = 20 km s⁻¹ (see Section 3.1 for a formal definition of these quantities).