0.5–2 keV observed flux in units of 10⁻¹⁴ erg s⁻¹ cm⁻²;

2–10 keV observed flux in units of 10⁻¹⁴ erg s⁻¹ cm⁻²;

2–10 keV unabsorbed luminosity;

α_OX computed using extinction-corrected 2500 Å and unabsorbed 2 keV luminosities. The with 2 keV luminosity from unabsorbed power-law modelling is reported in parenthesis.;

Difference between the measured α_OX and predicted one based on the α_OX − L₂₅₀₀ Å relation from Just et al. (2007). In this luminosity regime, the recently derived α_OX − L₂₅₀₀ Å relation by Lusso & Risaliti (2016), which was derived for the X-ray detected quasars with E(B − V) < 0.1 and 1.6 ≤ Γ ≤ 2.8, predict α_OX values ∼0.03 smaller (i.e. more negative) than the Just et al. (2007) ones. In parenthesis, that adopts with 2 keV luminosity from unabsorbed power-law modelling is reported;

For this source the flat Γ value is consistent with the canonical Γ = 1.8 − 2 derived for local PG quasars (Piconcelli et al. 2015). We verified that the inferred low luminosity is not the result of the flat best-fit photon index. Hence, we fitted the data with Γ = 1.9 and obtained a luminosity value, which is only 0.2 dex higher than estimated, therefore confirming its low X-ray luminosity.