Computed spectral profiles of C iv  1548 Å (thick line) and C iv  1550 Å (thin line). The blueshifted spectral component corresponds to Volume 1 and Volume 2 corresponds to the central component with zero Doppler shift. All profiles are computed with an incident intensity of 8 × 10⁴ erg s^-1 cm^-2 sr^-1 Å^-1, and Ω = 0.25π for panels a) to c) and 0.2π for panel d). The spectral components intensity ratios R₁ and R₂ are indicated in the panels. For panels a) to c), R₁/R₂ ≃ 1.3 and for panel d) R₁/R₂ ≃ 1.1. In all cases, n_e1 = 5 × 10⁸ cm^-3, T₁ = 10⁵ K. n_e2 = 5 × 10⁹ cm^-3 (panels a) and d)) and n_e2 = 5 × 10¹⁰ cm^-3 (panels b) and c)).