OM10-cosmoDC2 mapping. We “paint on” host galaxies from the cosmoDC2 catalog (outlined in Section 2.1.3) to systems in the OM10 catalog (outlined in Section 2.1). Nearest neighbor mapping: to obtain a mapping between the two catalogs, we map AGN in OM10 to AGN in cosmoDC2 using their redshift and absolute magnitude and use their corresponding host galaxy. Left panel: the red OM10 systems are mapped to the blue cosmoDC2 systems. The blue points are a subset of the gray points. Middle panel: we demonstrate the scatter of the OM10-cosmoDC2 system mapping along the AGN redshift axis. Right panel: we demonstrate the scatter of the OM10-cosmoDC2 system mapping along the AGN i-band absolute brightness (AB mag) axis.