# [OIII] Emission Line Properties in a New Sample of Heavily Reddened Quasars at $z>2$

## TL;DR

This study analyzes the [OIII] emission line properties in a new sample of heavily reddened quasars at redshifts greater than 2, revealing strong outflows and suggesting dust is located on galactic scales.

## Contribution

First comparison of [OIII] line properties in high-luminosity obscured quasars to unobscured ones at similar redshifts and luminosities, providing insights into outflows and dust location.

## Key findings

- Broad wings in [OIII] lines indicate strong outflows.
- No significant kinematic difference between reddened and unobscured quasars.
- Dust likely resides on galactic scales outside the [OIII] emitting region.

## Abstract

We present VLT-SINFONI near infra-red spectra of 26 new heavily reddened quasar candidates selected from the UKIDSS-LAS, VISTA VHS and VIKING imaging surveys. This new sample extends our reddened quasar search to both brighter and fainter luminosities. 25 of the 26 candidates are confirmed to be broad line quasars with redshifts $0.7<z<2.6$ and dust extinctions $0.5<E(B-V)<3.0$. Combining with previously identified samples, we study the H$\alpha$, H$\beta$ and [OIII] emission line properties in 22 heavily reddened quasars with $L_{bol}\approx 10^{47}$ erg/s and $z>2$. We present the first comparison of the [OIII] line properties in high luminosity obscured quasars to a large sample of 111 unobscured quasars in the same luminosity and redshift range. Broad wings extending to velocities of 2500 km/s are seen in the [OIII] emission line profiles of our reddened quasars, suggesting that strong outflows are affecting the ionised gas kinematics. However, we find no significant difference between the kinematics of the [OIII] emission in reddened and unobscured quasars when the two samples are matched in luminosity and redshift. Our results are consistent with a model where quasar-driven outflows persist for some time after the obscuring dust has been cleared from along the line of sight. Assuming the amount of ionised gas in obscured and unobscured quasars is similar, we use the equivalent width distribution of the [OIII] emission to constrain the location of the obscuring dust in our reddened quasars. We find that the dust is most likely to be located on galactic scales, outside the [OIII] emitting region.