Plot of R magnitude vs. 0.5–2.0 keV flux for X‐ray sources. Plotted are the 12 Chandra HDF‐N area sources in Table 2 that are detected in the soft band (stars), the 221.9 ks Chandra sources from H01 (triangles), the 100 ks Chandra sources from Mushotzky et al. (2000; open circles), and the ROSAT sources from Schmidt et al. (1998; filled circles). The slanted lines have been calculated following § 5.1 of H01; they show the typical range of X‐ray–to–R‐band flux observed for luminous AGNs in the local universe.