Quasar Outflow Contribution to AGN Feedback: Observations of QSO SDSS J0838+2955

TL;DR

This study analyzes a quasar's outflow using spectral data, revealing its properties and suggesting it significantly impacts galaxy evolution through AGN feedback.

Contribution

It provides detailed measurements of the outflow's physical properties and quantifies its kinetic energy contribution to AGN feedback, a novel detailed case study.

Findings

Outflow located at ~3.3 kpc from the AGN.

Kinetic luminosity of outflow is about 1.4% of the QSO's bolometric luminosity.

Outflow has a significant potential to influence galaxy evolution.

Abstract

We present a detailed analysis of the Astrophysical Research Consortium 3.5 m telescope spectrum of QSO SDSS J0838+2955. The object shows three broad absorption line (BAL) systems at 22,000, 13,000, and 4900 km s^-1 blueshifted from the systemic redshift of z=2.043. Of particular interest is the lowest velocity system that displays absorption from low-ionization species such as Mg II, Al II, Si II, Si II*, Fe II and Fe II*. Accurate column densities were measured for all transitions in this lowest velocity BAL using an inhomogeneous absorber model. The ratio of column densities of Si II* and Fe II* with respect to their ground states gave an electron number density of log n_e (cm^-3) = 3.75 +/- 0.22 for the outflow. Photoionization modeling with careful regards to chemical abundances and the incident spectral energy distribution predicts an ionization parameter of log U_H = -1.93 +/- 0.21 and a hydrogen column density of log N_H (cm^-2) = 20.80 +/- 0.28. This places the outflow at 3.3+1.5-1.0 kpc from the central AGN. Assuming that the fraction of solid angle subtended by the outflow is 0.2, these values yield a kinetic luminosity of (4.5+3.1-1.8) x 10^45 erg s^-1, which is (1.4+1.1-0.6)% the bolometric luminosity of the QSO itself. Such large kinetic luminosity suggests that QSO outflows are a major contributor to AGN feedback mechanisms.