Tracing outflows in the AGN forbidden region with SINFONI

TL;DR

This study uses integral field spectroscopy to observe and characterize high-velocity, kiloparsec-scale ionized outflows in AGN hosts at z > 1, providing insights into their morphology, dynamics, and potential driving mechanisms.

Contribution

It presents new spatially-resolved kinematic data of AGN outflows at high redshift, highlighting the prevalence of extended outflows and discussing their possible origins from star formation or AGN activity.

Findings

Detected high-velocity outflows (~600-1900 km/s) in at least 3 of 5 targets.

Estimated mass outflow rates of approximately 1-10 solar masses per year.

Observed outflows are on kiloparsec scales and may be driven by star formation or AGN radiation.

Abstract

AGN driven outflows are invoked in numerical simulations to reproduce several observed properties of local galaxies. The z > 1 epoch is of particular interest as it was during this time that the volume averaged star formation and the accretion rate of black holes were maximum. Radiatively driven outflows are therefore believed to be common during this epoch. We aim to trace and characterize outflows in AGN hosts with high mass accretion rates at z > 1 using integral field spectroscopy. We obtain spatially-resolved kinematics of the [OIII]5007 line in two targets which reveal the morphology and spatial extension of the outflows. We present J and H+K band SINFONI observations of 5 AGNs at 1.2 < z < 2.2. To maximize the chance of observing radiatively driven outflows, our sample was pre-selected based on peculiar values of the Eddington ratio and the hydrogen column density of the surrounding interstellar medium. We observe high velocity (~600-1900 km/s) and kiloparsec scale extended ionized outflows in at least 3 of our targets, using [OIII]5007 line kinematics tracing the AGN narrow line region. We estimate the total mass of the outflow, the mass outflow rate, and the kinetic power of the outflows based on theoretical models and report on the uncertainties associated with them. We find mass outflow rates of ~1-10 M_sun/yr for the sample presented in this paper. Based on the high star formation rates of the host galaxies, the observed outflow kinetic power and the expected power due to the AGN, we infer that both star formation and AGN radiation could be the dominant source for the outflows. The outflow models suffer from large uncertainties, hence we call for further detailed observations for an accurate determination of the outflow properties to confirm the exact source of these outflows.