A Mini-BAL Outflow at 900 pc from the Central Source: VLT/X-shooter Observations

Abstract

We determine the physical conditions and location of the outflow material seen in the mini-BAL quasar SDSS J1111+1437 (z = 2.138). These results are based on the analysis of a high S/N, medium-resolution VLT/X- shooter spectrum. The main outflow component spans the velocity range -1500 to -3000 km s${}^{-1}$ and has detected absorption troughs from both high-ionization species: C IV , N V , O VI , Si IV , P V , and S IV ; and low-ionization species: H I , C II , Mg II , Al II , Al III , Si II , and Si III . Measurements of these troughs allow us to derive an accurate photoionization solution for this absorption component: a hydrogen column density, log ( N H ) = 21.47 ${}_{-0.27}^{+0.21}$ cm${}^{-2}$ and ionization parameter, log (U_H) = -1.23${}_{-0.25}^{+0.20}$. Troughs produced from the ground and excited states of S IV combined with the derived U_H value allow us to determine an electron number density of log (n_e) = 3.62${}_{-0.11}^{+0.09}$ cm${}^{-3}$ and to obtain the distance of the ionized gas from the central source: R = 880${}_{-260}^{+220}$ pc.

9 pages, 6 figures, 2 tables. Published, 2018, ApJ, 858, 39