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

Abstract

We report a clear detection of He I*lambda lambda 2946, 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 Ly alpha, C II, and Si IV, as well as optical emission lines, such as H alpha, H beta, and [O III]. Using photoionization simulations, we constrained the physical conditions of the outflow to a hydrogen column density of N-H approximate to 10(21.3) cm(-2), an ionization parameter of U approximate to 10(-1.4), and a hydrogen number density of n(H) approximate to 10(3.6) cm(-3), and located its radial distance at r(abs) similar to 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) similar to 3.0 x 10(17)-1.2 x 10(18) 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 similar to 1700 km s(-1) and a width of FWHM similar to 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 similar to 4%, its mass-loss rate to be similar to 70 M(circle dot)yr(-1) and its kinetic luminosity to be similar to 3.2 x 10(44) 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.