Elemental Abundances from Intrinsic QSO Emission and Absorption Lines

Several studies have shown that the column densities inferred from broad absorption lines (BALs) require extremely high metallicities and phosphorus overabundances – apparently in conflict with other abundance diagnostics. Here I use HST spectroscopy of the BALQSO PG 1254+047 to argue that the BALs abundance estimates are incorrect, because partial line-of-sight coverage of the continuum source(s) has led to gross underestimates of the line optical depths and column densities. I claim that the significant presence of P V λ1118,1128 absorption in this and other BALQSOs identifies the saturated absorption-line spectrum. This interpretation implies that the total column densities are at least ten times larger than previous estimates, namely log NH (cm ) ∼> 22.0. The outflowing BAL gas, at velocities from −15,000 to −27,000 km s in PG 1254+047, is therefore a strong candidate for the X-ray absorber in BALQSOs. If this high-column density outflow is radiately accelerated, it must originate ∼<0.1 pc from the QSO.