Redshift distributions of the MQN01 high-confidence spectroscopic sample (black histogram) and of the UBR-selected LBGs with secure spectroscopic redshift from MUSE (hatched gray histogram). These are compared to the “MUSE-FIELD” sample and normalized by the surveyed area. The redshift of the central QSO is marked by an orange vertical line. The inset shows the velocity distribution of the MUSE galaxies and of the LBGs relative to the redshift of the QSO. The line-of-sight velocity window corresponding to |Δv|≤1000 km s⁻¹ is highlighted by dotted vertical lines.