The Properties of Low-Redshift FeLoBAL Quasars: III. The Location and Geometry of the Outflows

Abstract

We present continued analysis of a sample of low-redshift iron low-ionization broad absorption-line quasars (FeLoBALQs). Choi et al. (2022) presented $SimBAL$ spectral analysis of BAL outflows in 50 objects. Leighly et al. (2022) analyzed optical emission lines of 30 of those 50 objects and found that they are characterized by either a high accretion rate ($L_\mathrm{Bol}/L_\mathrm{Edd}>0.3$) or low accretion rate ($0.03<L_\mathrm{Bol}/L_\mathrm{Edd}<0.3$). We report that the outflow velocity is inversely correlated with the BAL location among the high accretion rate objects, with the highest velocities observed in the parsec-scale outflows. In contrast, the low Eddington ratio objects showed the opposite trend. We confirmed the known relationship between outflow velocity and $L_\mathrm{Bol}/L_\mathrm{Edd}$, and found that the scatter plausibly originates in the force multiplier (launch radius) in the low (high) accretion rate objects. A log volume filling factor between $-6$ and $-4$ was found in most outflows, but was as high as $-1$ for low-velocity compact outflows. We investigated the relationship between the observed [O III] emission and that predicted from the BAL gas. We found that these could be reconciled if the emission-line covering fraction depends on Seyfert type and BAL location. The difference between the predicted and observed [O III] luminosity is correlated with the outflow velocity, suggesting that [O III] emission in high Eddington ratio objects may be broad and hidden under Fe II emission. We suggest that the physical differences in the outflow properties as a function of location in the quasar and accretion rate point to different formation, acceleration, and confinement mechanisms for the two FeLoBALQ types.