Galactic-scale Broad Absorption Line Outflow in the Quasar SDSS J144842.45+042403.1

Abstract

Abstract We report a clear detection of He i*λλ2946, 3189, and 3889 broad absorption line (BAL) in the low-ionization BAL (LoBAL) quasar SDSS J144842.45+042403.1. We also detected new BALs, including Lyα, C ii, and Si iv, as well as optical emission lines, such as Hα, Hβ, and [O iii]. Using photoionization simulations, we constrained the physical conditions of the outflow to a hydrogen column density of N H ≈ 1021.3 cm−2, an ionization parameter of U ≈ 10−1.4, and a hydrogen number density of n H ≈ 103.6 cm−3, and located its radial distance at r abs ∼ 1.52 kpc from the central engine. The photoionization model predicts the presence of a Lyman limit system with H i column density of N H i ∼ 3.0 × 1017–1.2 × 1018 cm−2, which is confirmed by the GALEX photometry. Interestingly, we found that the [O iii] emission line doublet has an outflow component at a large blueshift of v ∼ 1700 km s−1 and a width of FWHM ∼ 5000 km s−1. Assuming that we are witnessing the same outflow in both emission and absorption lines, we estimate the global covering fraction of the emission line outflow to be ∼4%, its mass-loss rate to be ∼70 M ⊙ yr−1 and its kinetic luminosity to be ∼3.2 × 1044 erg s−1. SDSS J1448+0424 is a representative example of a significant fraction of LoBAL quasars, which deserves further studies to understand the connection between the growth of supermassive black holes and the evolution of their host galaxies.