Galactic-scale Emission-line Outflow from the Radio-loud Quasar 3C 191

Abstract

Quasar feedback is routinely invoked as an indispensable ingredient in galaxy formation models. Galactic outflows are a crucial agent of quasar feedback that frequently manifest themselves in absorption and emission lines. Measuring the size and energetics of outflows based on absorption lines remains a challenge, and integral field spectroscopy (IFS) mapping in emission lines is complementary. We present Very Large Telescope (VLT)/SINFONI IFS mapping of quasar 3C 191 at z ∼ 2, in which the outflow has been analyzed in absorption line spectroscopy. Three components are found based on the morphology and kinetics of [O iii ]-emitting gas: an unshifted component, which is consistent with the systemic redshift and the location of the nucleus, a blueshifted in the north, and a redshifted in the south. The latter two components have velocities ∼600 km s ^−1 and projected extents of 5 and 11 kpc, respectively, suggesting a biconical outflow structure. The blueshifted component’s velocity is consistent with that derived from absorption lines. Using the electron density measured by the absorption lines and the luminosity and velocity of [O iii ] outflow, we derive the mass outflow rate to be $\dot{M}$ ∼ 9.5–13.4 M _⊙ yr ^−1 and kinetic luminosity ${\dot{E}}_{\mathrm{kin}}$ ∼ 2.6–3.7 × 10 ^42 erg s ^−1 , consistent with absorption line analyses with the VLT/X-shooter spectrum. The kinetic luminosity is only 0.01% of the bolometric luminosity, rendering a relatively weak outflow compared to typical expectation for effective feedback.

Keywords

• Quasars
• Active galactic nuclei