Distributions of galaxy line-of-sight velocities in the MQN01 field. Right axis: Velocity distribution of galaxies in the MQN01 field either detected in their CO(4–3) lines in our ALMA band 6 survey (orange bins) or having high-fidelity spectroscopic redshift within |Δv_QSO|< 4000 km s⁻¹ measured from MUSE data (violet bins). The blue hatched bins are the distribution of galaxy velocities in the core. Left axis: Cumulative distribution of the whole sample and that of the core (black and blue lines, respectively). The light blue curve is the theoretical prediction for a Gaussian distribution of velocities with central value and dispersion as reported in the legend. The gray band represents the 1σ confidence interval.