2025RNAAS...9..164C

In this research note, we consider a sample of 34 X-ray-selected active galactic nucleus (AGN) in the 500 ks Chandra/ACIS-I observation of the J1030+0524 field, which were identified through optical spectroscopy. The targets span a redshift range z ∼ 0.1-1.5 and feature detection of [O III]λ5007, [Ne V]λ3426, or both. We investigated the ratio between their absorption-corrected 2-10 keV luminosity, as derived from X-ray spectroscopy, versus [O III] and/or [Ne V] luminosity, and compared our measurements with literature results. Most targets align with the X-ray versus line luminosity relations in the literature, with a notable exception: the type 2 AGN XID 361 at z = 0.83 is significantly less luminous in the X-rays than what would be expected from its high-ionization lines, calling for heavy, Compton-thick absorption that was overlooked through X-ray spectroscopy.