N_H plotted against Eddington ratio. Sources marked in red are the selected candidates. Solid grey contours are eFEDS sample after applying the cut on redshift (z > 0.5) and dashed grey contours show the full eFEDS sample. ID 608 (Brusa et al. 2022; blue star) and the sources isolated from Sect. 2.2 are shown with violet circles. The black thick dashed line and curve represent the region N_H > 10^21.5 cm⁻² and λ_Edd > effective Eddington limit. The dotted curve (thick and thin) is the effective Eddington limit for different values of N_H (Fabian et al. 2009).