Velocity shift of z_ALMA with respect to z_UV, Δv, as a function of z_ALMA (see Table 3). Hot DOGs are displayed as red squares. The z ≃ 4.7 IRQs from Trakhtenbrot et al. (2017) and Nguyen et al. (2020) are represented as yellow pentagons. The compilation of z ≳ 6 OpQs from Decarli et al. (2018) are displayed as green stars when the optical redshift is based on the Mg II emission line, and as blue stars when other lines or methods are used. Star-forming galaxies at 4 < z < 6 from the ALPINE survey (Cassata et al. 2020) are shown as pink pentagons.