C II λ1334 and Lyβ absorption lines for seven directions of observation. The vertical dashed lines highlight the wavelength of the fluorescent channels. The spectra are arranged in increasing order of escape fraction of ionizing photons in the direction of observation, f_esc (as computed in Sect. 2.6). The noise is Monte-Carlo noise, due to a sampling of the luminosity with a finite number of photon packets. The spectra are smoothed with a Gaussian kernel with FWHM = 20 km s⁻¹. The aperture diameter for the mock observation is a fifth of the virial radius, which corresponds to about 5.6 kpc, or 0.75″ at z = 3. No observational effects such as noise, spectral binning, Earth atmosphere, or MW alterations are considered. We note that the x-axis in the first two rows of the second column differ from the others.