α_ox gradient as function of Eddington luminosity log λ_Edd. The position of PG 0043+039 (in the year 2022) is highlighted (filled purple hexagon). The other AGNs are from Laurenti et al. (2022), Lusso et al. (2010), Liu et al. (2021), and Zappacosta et al. (2020) divided into different regimes of bolometric luminosity as presented by Laurenti et al. (2022) (their Fig. 5, right panel). The solid line represents the best-fit relation from Lusso et al. (2010). The dashed lines give the 1σ spread of their relation.