# Far-infrared emission in luminous quasars accompanied by nuclear outflows

## TL;DR

This study links bright far-infrared emission in luminous quasars to powerful nuclear outflows, suggesting a specific evolutionary phase with high accretion rates and active feedback impacting galaxy evolution.

## Contribution

It provides observational evidence connecting FIR-bright quasars with strong outflows and proposes a phase of high accretion and feedback in quasar evolution.

## Key findings

- FIR-bright quasars exhibit significant CIV blueshifts indicating strong outflows.
- No difference in optical colors between FIR-bright and typical quasars.
- FIR emission may be due to star formation or dust illuminated by the quasar.

## Abstract

Combining large-area optical quasar surveys with the new far-infrared Herschel-ATLAS Data Release 1, we search for an observational signature associated with the minority of quasars possessing bright far-infrared (FIR) luminosities. We find that FIR-bright quasars show broad CIV emission line blueshifts in excess of that expected from the optical luminosity alone, indicating particularly powerful nuclear outflows. The quasars show no signs of having redder optical colours than the general ensemble of optically-selected quasars, ruling out differences in line-of-sight dust within the host galaxies. We postulate that these objects may be caught in a special evolutionary phase, with unobscured, high black hole accretion rates and correspondingly strong nuclear outflows. The high FIR emission found in these objects is then either a result of star formation related to the outflow, or is due to dust within the host galaxy illuminated by the quasar. We are thus directly witnessing coincident small-scale nuclear processes and galaxy-wide activity, commonly invoked in galaxy simulations which rely on feedback from quasars to influence galaxy evolution.