The Quasar Outflow Contribution to AGN Feedback: VLT Measurements of SDSS J0318-0600

TL;DR

This study uses high-resolution VLT spectra to analyze a quasar outflow, estimating its physical properties and demonstrating its significant role in AGN feedback through substantial mass flux and kinetic energy.

Contribution

It provides detailed measurements of ionic column densities, electron density, dust properties, and outflow distances, highlighting the outflow's impact on galaxy evolution.

Findings

Outflow mass flux of approximately 120 solar masses per year.

Kinetic luminosity about 0.1% of the quasar's bolometric luminosity.

Outflow distances estimated at 6 and 18 kpc, with 6 kpc considered more plausible.

Abstract

We present high spectral resolution VLT observations of the BAL quasar SDSS J0318-0600. This high quality data set allows us to extract accurate ionic column densities and determine an electron number density of n_e=10^3.3 +/- 0.2 cm^-3 for the main outflow absorption component. The heavily reddened spectrum of SDSS J0318-0600 requires purely silicate dust with a reddening curve characteristic of predominately large grains, from which we estimate the bolometric luminosity. We carry out photoionization modeling to determine the total column density, ionization parameter and distance of the gas and find that the photionization models suggest abundances greater than solar. Due to the uncertainty in the location of the dust extinction, we arrive at two viable distances for the main ouflow component from the central source, 6 and 18 kpc, where we consider the 6 kpc location as somewhat more physically plausable. Assuming the canonical global covering of 20% for the outflow and a distance of 6 kpc, our analysis yields a mass flux of 120 M_sun yr^-1 and a kinetic luminosity that is ~0.1% of the bolometric luminosity of the object. Should the dust be part of the outflow, then these values are ~4x larger. The large mass flux and kinetic luminosity make this outflow a significant contributor to AGN feedback processes.