It is the twentieth anniversary of the publication of the seminal papers by Magorrian et al. and Silk & Rees which, along with other related work, ignited an explosion of publications connecting active galactic nuclei (AGN)-driven outflows to galaxy evolution. With a surge in observations of AGN outflows, studies are attempting to directly test AGN feedback models using the outflow properties. With a focus on outflows traced by optical and CO emission lines, we discuss significant challenges which greatly complicate this task from both an observational and theoretical perspective. We highlight observational uncertainties involved, and the assumptions required, when deriving kinetic coupling efficiencies (i.e., outflow kinetic power as a fraction of AGN luminosity) from typical observations. Based on recent models we demonstrate that extreme caution should taken when comparing observationally-derived kinetic coupling efficiencies to coupling efficiencies from fiducial feedback models.During the 1950s and 1960s, it was established that a massive and powerful energy source was required to explain the exceptional luminosities generated by a class of extragalactic objects now known as active galactic nuclei (AGN)[1, 2, 3]. The energy source was heavily debated[4, 5] but the prevailing idea was the accretion of matter onto black holes residing within the nuclei of galaxies [6], that grow at a rate ofṀ BH and have bolometric luminosities of,The inferred very high mass-to-energy conversion efficiency of η r ≈ 0.1 [7,8] and high black hole masses (i.e., millions to billions that of the Sun) implies that over the lifetime of a typical black hole, the net energy emitted greatly exceeds the binding energy of their host galaxies [9]. It was quickly appreciated that the tremendous amount of energy from AGN could influence galaxy evolution. With effective mechanical (via the jets of charged particles observed in some AGN) or radiative coupling, it became clear that they could heat gas in and around galaxies [10,11]. Consequently, AGN became a popular explanation for the "excess energy" observed in galaxy clusters [12]. The constant heating of hot gas around galaxies is sometimes referred to as a "maintenance mode" of AGN feedback [9] and now has convincing evidence due to observed X-ray cavities associated with radio jets and lobes [13].An "explosion" of energy from the most luminous AGN (quasars) was also presented from the 1980s as a mechanism to enrich the intergalactic medium and trigger star formation, even to the point of forming entire galaxies [14,15]. Furthermore, in 1988 Sanders et al. proposed that ultraluminous infrared galaxies host dust enshrouded quasars whose radiation pressure will subsequently drive high velocity (≈100 km s −1 ), high mass outflows that potentially remove or destroy molecular gas [16]. In this article we focus on warm ionised and cold molecular outflows, driven by strong AGN radiation fields or radio jets, and their impact upon the host galaxies. This is sometimes referred to as a "quasar mod...

Aims. The SINFONI survey for Unveiling the Physics and Effect of Radiative feedback (SUPER) aims to trace and characterise ionised gas outflows and their impact on star formation in a statistical sample of X-ray selected active galactic nuclei (AGN) at z ∼ 2. We present the first SINFONI results for a sample of 21 Type 1 AGN spanning a wide range in bolometric luminosity (log Lbol = 45.4–47.9 erg s−1). The main aims of this paper are to determine the extension of the ionised gas, characterise the occurrence of AGN-driven outflows, and link the properties of such outflows with those of the AGN. Methods. We used adaptive optics-assisted SINFONI observations to trace ionised gas in the extended narrow line region using the [O III] λ5007 line. We classified a target as hosting an outflow if its non-parametric velocity of the [O III] line, w80, was larger than 600 km s−1. We studied the presence of extended emission using dedicated point-spread function (PSF) observations, after modelling the PSF from the Balmer lines originating from the broad line region. Results. We detect outflows in all the Type 1 AGN sample based on the w80 value from the integrated spectrum, which is in the range ∼650–2700 km s−1. There is a clear positive correlation between w80 and the AGN bolometric luminosity (> 99% correlation probability), and the black hole mass (98% correlation probability). A comparison of the PSF and the [O III] radial profile shows that the [O III] emission is spatially resolved for ∼35% of the Type 1 sample and the outflows show an extension up to ∼6 kpc. The relation between maximum velocity and the bolometric luminosity is consistent with model predictions for shocks from an AGN-driven outflow. The escape fraction of the outflowing gas increases with the AGN luminosity, although for most galaxies, this fraction is less than 10%.

Theoretical models of galaxy formation suggest that the presence of an active galactic nucleus (AGN) is required to regulate the growth of its host galaxy through feedback mechanisms, produced by, for example, AGN-driven outflows. Although many observational studies have revealed that such outflows are common both at low and high redshift, a comprehensive picture is still missing. In particular, the peak epoch of galaxy assembly (1 < z < 3) has been poorly explored so far, and current observations in this redshift range are mostly limited to targets with high chances to be in an outflowing phase. This paper introduces SUPER (a SINFONI Survey for Unveiling the Physics and Effect of Radiative feedback), an ongoing ESO's VLT/SINFONI Large Programme. SUPER will perform the first systematic investigation of ionized outflows in a sizeable and blindly-selected sample of 39 X-ray AGN at z ∼ 2, which reaches high spatial resolutions (∼2 kpc) thanks to the adaptive optics-assisted IFS observations. The outflow morphology and star formation in the host galaxy will be mapped through the broad component of [O iii]λ5007 and the narrow component of Hα emission lines. The main aim of our survey is to infer the impact of outflows on the on-going star formation and to link the outflow properties to a number of AGN and host galaxy properties. We describe here the survey characteristics and goals, as well as the selection of the target sample. Moreover, we present a full characterization of its multi-wavelength properties: we measure, via spectral energy distribution fitting of UV-to-FIR photometry, stellar masses (4 × 10 9 −2 × 10 11 M ), star formation rates (25−680 M yr −1 ) and AGN bolometric luminosities (2 × 10 44 −8 × 10 47 erg s −1 ), along with obscuring column densities (up to 2 × 10 24 cm −2 ) and luminosities in the hard 2−10 keV band (2 × 10 43 −6 × 10 45 erg s −1 ) derived through X-ray spectral analysis. Finally, we classify our AGN as jetted or non-jetted according to their radio and FIR emission.

Context. Feedback from active galactic nuclei (AGN) is thought to play an important role in quenching star formation in galaxies. However, the efficiency with which AGN dissipate their radiative energy into the ambient medium remains strongly debated. Aims. Enormous observational efforts have been made to constrain the energetics of AGN feedback by mapping the kinematics of the ionized gas on kpc scale. We study how the observed kinematics and inferred energetics are affected by beam smearing of a bright unresolved narrow-line region (NLR) due to seeing. Methods. We re-analyse optical integral-field spectroscopy of a sample of twelve luminous unobscured quasi-stellar objects (QSOs) (0.4 < z < 0.7) previously presented in the literature. The point-spread function (PSF) for the observations is directly obtained from the light distribution of the broad Hβ line component. Therefore, we are able to compare the ionized gas kinematics and derived energetics of the total, truly spatially extended, and unresolved [O iii] emission. Results. We find that the spatially resolved [O iii] line width on kpc scales is significantly narrower than the one before PSF deblending. The extended NLRs (ENLRs) appear intrinsically offset from the QSO position or more elongated which can be interpreted in favour of a conical outflow on large scales while a spherical geometry cannot be ruled out for the unresolved NLR. We find that the kinetic power at 5 kpc distance based on a spherical model is reduced by two orders of magnitude for a conical outflow and one order of magnitude for the unresolved NLR after PSF deblending. This reduced kinetic power corresponds to only 0.01−0.1 per cent of the bolometric AGN luminosity. This is smaller than the 5−10% feedback efficiency required by some cosmological simulations to reproduce the massive galaxy population. The injected momentum fluxes are close or below the simple radiation-pressure limit L bol /c for the conical outflow model for the NLR and ENLR when beam smearing is considered. Conclusions. Integral-field spectroscopy is a powerful tool to investigate the energetics of AGN outflows, but the impact of beam smearing has to be taken into account in the high contrast regime of QSOs. For the majority of observations in the literature, this has not been addressed carefully so that the incidence and energetics of presumed kpc-scale AGN-driven outflows still remain an unsolved issue, from an observational perspective.

Context. Although studying outflows in the host galaxies of Active Galactic Nuclei (AGN) have become the forefront of extra-galactic astronomy in recent years, estimating the energy associated with these outflows have been a major challenge. Determination of the energy associated with an outflow often involves an assumption of uniform density in the Narrow Line Region (NLR), which span a wide range in literature leading to large systematic uncertainties in energy estimation. Aims. In this paper, we present electron density maps for a sample of outflowing and non-outflowing Seyfert galaxies at z<0.02 drawn from the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7) and understand the origin and values of the observed density structures to reduce the systematic uncertainties in outflow energy estimation. Methods. We use the ratio of the [S ii]λ6716,6731 emission lines to derive spatially resolved electron densities ( 50-2000 cm −3 ). Using optical Integral Field Unit observations from the WiFeS instrument, we are able to measure densities across the central 2-5 kpc of the selected AGN host galaxies. We compare the density maps with the positions of the H ii regions derived from the narrow Hα component, ionization maps from [O iii], and spatially resolved BPT diagrams, to infer the origin of the observed density structures. We also use the electron density maps to construct density profiles as a function of distance from the central AGN.Results. We find a spatial correlation between the sites of high star formation and high electron density for targets without an active ionized outflow. The non-outflowing targets also show an exponential drop in the electron density as a function of distance from the center, with a mean exponential index of ∼0.15. The correlation between the star forming sites and electron density ceases for targets with an outflow. The density within the outflowing medium is not uniform and shows both low and high density sites, most likely due to the presence of shocks and highly turbulent medium. We compare these results in the context of previous results obtained from fiber and slit spectra.

Context. Active galactic nucleus (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 at their maximum. Radiatively driven outflows are therefore believed to be common during this epoch. Aims. 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 [O iii] λ5007 line in two targets which reveal the morphology and spatial extension of the outflows. Methods. We present SINFONI observations in the J band and the H + K band of five 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 −1 ) and kiloparsec scale extended ionized outflows in at least three of our targets, using [O iii] λ5007 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. Results. We find mass outflow rates of ∼1−10 M /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.

As part of our KMOS AGN Survey at High-redshift (KASHz), we present spatiallyresolved VLT/KMOS and VLT/SINFONI spectroscopic data and ALMA 870µm continuum imaging of eight z=1.4-2.6 moderate AGN (L 2−10kev = 10 42 −10 45 ergs s −1 ). We map [O iii], Hα and rest-frame FIR emission to search for any spatial anti-correlation between ionised outflows (traced by the [O iii] line) and star formation (SF; traced by Hα and FIR), that has previously been claimed for some high-z AGN and used as evidence for negative and/or positive AGN feedback. Firstly, we conclude that Hα is unreliable to map SF inside our AGN host galaxies based on: (i) SF rates inferred from attenuation-corrected Hα can lie below those inferred from FIR; (ii) the FIR continuum is more compact than the Hα emission by a factor of ∼ 2 on average; (iii) in half of our sample, we observe significant spatial offsets between the FIR and Hα emission, with an average offset of 1.4 ± 0.6 kpc. Secondly, for the five targets with outflows we find no evidence for a spatial anti-correlation between outflows and SF using either Hα or FIR as a tracer. This holds for our re-analysis of a famous z=1.6 X-ray AGN ('XID 2028') where positive and negative feedback has been previously claimed. Based on our results, any instantaneous impact on SF by ionised outflows must be subtle, either occurring on scales below our resolution, or on long timescales.

We use a sample of powerful z≈0.1 type 2 quasars (‘obscured’; log [LAGN/erg s−1]≳45), which host kiloparsec-scale ionized outflows and jets, to identify possible signatures of AGN feedback on the total molecular gas reservoirs of their host galaxies. Specifically, we present Atacama Pathfinder EXperiment (APEX) observations of the CO(2–1) transition for nine sources and the CO(6–5) for a subset of three. We find that the majority of our sample reside in starburst galaxies (average specific star formation rates of 1.7 Gyr−1), with the seven CO-detected quasars also having large molecular gas reservoirs (average Mgas=1.3× 1010 M⊙), even though we had no pre-selection on the star formation or molecular gas properties. Despite the presence of quasars and outflows, we find that the molecular gas fractions (Mgas/M⋆=0.1–1.2) and depletion times (Mgas/SFR=0.16–0.95 Gyr) are consistent with those expected for the overall galaxy population with matched stellar masses and specific star formation rates. Furthermore, for at least two of the three targets with the required measurements, the CO(6–5)/CO(2–1) emission-line ratios are consistent with star formation dominating the CO excitation over this range of transitions. The targets in our study represent a gas-rich phase of galaxy evolution with simultaneously high levels of star formation and nuclear activity; furthermore, the jets and outflows do not have an immediate appreciable impact on the global molecular gas reservoirs.