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Quasar Q0059–2735, one of the first known iron low-ionization broad-absorption-line quasars (FeLoBAL), has a plethora of outflow absorption features at different velocities. Given multiple outflow systems, their troughs from high-ionization transitions form very wide BAL features, e.g. C iv troughs extend from ∼−1000 to −25 000 km s−1. The troughs from low-ionization transitions show more than 1000 narrow absorption lines (NALs) with velocities from −1000 to −3000 km s−1. These include troughs from iron-peak elements, e.g. Fe ii, Fe iii, Cr ii, Mn ii, Ni ii, and Co ii, which are rarely detected in quasar outflows. Most of these troughs are non-black saturated. We constrain the physical conditions of the NALs by fitting the observed Fe ii and Fe iii absorption troughs. We find that the Fe ii absorption arises from a region with an electron temperature (Te) of ∼8000 K and an electron number density (ne) of ∼108 cm−3. The same model also fits well the troughs from other iron-peak elements. In contrast to the Fe ii lines, Fe iii lines are formed in a hotter region, i.e. Te ∼20 000 K. To fit the Fe ii and Fe iii lines simultaneously in a single photoionized cloud, they require a supersolar iron abundance and/or other heating mechanisms for the Fe iii region. The distance (R) of the outflows to the central quasar is determined to be ∼40 pc. The high-resolution data afforded by the Very Large Telescope (VLT)/UVES observations from 2006 and 2018, along with the narrow lines, allow us to constrain the smallest outflow deceleration in any known quasars.

We analyze VLT/X-shooter data for 7 quasars, where we study the relationships between their broad absorption line (BAL) and emission line outflows. We find: 1) the luminosity of the [OIII] $\lambda$5007 emission profile decreases with increasing electron number density (n$_e$) derived from the BAL outflow in the same quasar, 2) the measured velocity widths from the [OIII] emission features and CIV absorption troughs in the same object are similar, and 3) the mean radial velocity derived from the BAL outflow is moderately larger than the one from the [OIII] emission outflow. These findings can be explained by the physical interpretation that the [OIII] and BAL outflow are different manifestations of the same wind. When we have outflows with smaller distances to the central source, their n$_e$ is higher. Therefore, the [OIII] emission is collisionally de-excited and the [OIII] luminosity is then suppressed. Comparisons to previous studies show that the objects in our sample exhibit broad [OIII] emission features similar to the ones in extremely red quasars (ERQs). This might imply that BAL quasars and ERQs have the same geometry of outflows or are at a similar evolutionary stage. We found that the physical parameters derived from the BAL outflows can explain the amount of observed [OIII] luminosity, which strengthens our claim of both BAL and [OIII] outflows are from the same wind. These estimates can be tested with upcoming James Webb Space Telescope observations., Comment: 16 pages, 9 figures

Blue-shifted Broad Absorption Lines (BALs) detected in quasar's spectra are indicative of AGN outflows. We show, using 2D hydrodynamical simulations, that disruption of interstellar clouds by a fast AGN wind can lead to formation of cold, dense high speed blobs that give rise to broad absorption features in the transmission spectrum of the AGN continuum source. For a wind velocity of $0.1 c$ and sufficiently high cloud density ($n_{c}$ < $10^4$ cm$^{-3}$, depending on size), absorption troughs with velocities up to about $3000$ km s$^{-1}$ can be produced. For slower winds and/or lower cloud density the anticipated velocity of the absorbing clouds should be smaller., 10 pages, 8 figures