Top panel: Projection of the 3D map representation of quasars from the SDSS DR16Q catalog; the color bar indicates the redshifts of each quasar. Bottom panel: Redshift distribution of the quasars, normalized by the total number of objects in the sample. The median of this distribution is marked by a distinct point for clarity. The subsample within the redshift range z ∈ [1.2, 2.8] is highlighted by vertical lines.