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J. Scholtz

Publications and source records attributed to J. Scholtz.

At least 37 records · Page 2Linked to original sources
arXiv2024

HYPERION. Interacting companion and outflow in the most luminous $z>6$ quasar

We present ALMA deep observations of the [CII] 158 $μ$m emission line and the continuum at 253 GHz and 99 GHz towards SDSS J0100+2802 at $z\simeq 6.3$, the most luminous quasi-stellar object (QSO) at z$>$6. J0100+2802 belongs to the HYPERION sample of luminous QSOs at $z\sim 6-7.5$. The observations (at 2.2" resolution in Band 3 and 0.9" resolution in Band 6) are optimized to detect extended emission around the QSO. We detect an interacting, tidally disrupted companion both in [CII], peaking at $z\sim 6.332$, and in continuum, stretching on scales up to 20 kpc from the quasar, with a knotty morphology. The higher velocity dispersion in the direction of the companion emission and the complex morphology of tidally stretched galaxy suggest a possible ongoing or future merger. For the newly-detected companion we derive a range of dust mass, $M_{\rm dust}=(0.3-2.6)\times 10^7\ \rm M_\odot$, and of star formation rate, SFR$=[35-344]\ \rm M_\odot$. This shows that both the QSO and its companion are gas rich and that a major merger may be at the origin of the boosted star formation. We also detect a broad blueshifted component in the [CII] spectrum, that we interpret as a gaseous outflow for which we estimate a mass outflow rate in the range $\dot{M}_{\rm out}=(118-269)\ \rm M_\odot\ yr^{-1}$. J0100+2802 was recently found to reside in a strong overdensity, however this close companion remained undetected by both previous higher resolution ALMA observations and by JWST-NIRCAM imaging. Our results highlight the importance of deep medium-resolution ALMA observations for the study of QSOs and their environment at the Epoch of Reionization.

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arXiv2023

Probing the interstellar medium of the quasar BRI0952-0115, an analysis of [CII], [CI], CO, OH, and H2O

The extent of the effect of active galactic nuclei (AGN) on their host galaxies at high-redshift is not apparent and studying this effect in the distant universe is a difficult process as the mechanisms of tracing AGN activity can often be inaccurately associated with intense star formation and vice versa. Our aim is to better understand the processes governing the interstellar medium (ISM) of the quasar BRI0952-0952 at z = 4.432, specifically with regard to the individual heating processes at work and to place the quasar in an evolutionary context. We analyzed ALMA archival bands 3, 4, and 6 data and combined the results with high-resolution band-7 ALMA observations of the quasar. We detect [C I] (2-1), [C II], CO(5-4), CO(7-6), CO(12-11), OH, H2O, and we report a tentative detection of OH+. We update the lensing model from Kade et al. (2023) and use the radiative transfer code MOLPOP-CEP to constrain the properties of the CO, [CI], and [CII] emission and suggest different possible scenarios for heating mechanisms within the quasar. Modeling from the CO SLED suggests that there are extreme heating mechanisms operating within the quasar in the form of star formation or AGN activity; however, with the current data it remains unclear which of the two is the preferred mechanism. The updated lensing model suggests a velocity gradient across the [C II] line, suggestive of on-going kinematical processes within the quasar. We find that the H2O emission in BRI0952 is likely correlated with star-forming regions of the ISM. We use the molecular gas mass from [C I] to calculate a depletion time for the quasar. We conclude that BRI 0952-0952 is a quasar with a significant AGN contribution while also showing signs of extreme starburst activity, indicating that the quasar could be in a transitional phase between a starburst-dominated stage and an AGN-dominated stage.

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arXiv2023

GA-NIFS: JWST/NIRSpec IFU observations of HFLS3 reveal a dense galaxy group at z~6.3

Massive, starbursting galaxies in the early Universe represent some of the most extreme objects in the study of galaxy evolution. One such source is HFLS3 (z~6.34), which was originally identified as an extreme starburst galaxy with mild gravitational magnification ($μ$~2.2). Here, we present new observations of HFLS3 with the JWST/NIRSpec IFU in both low (PRISM/CLEAR; R~100) and high spectral resolution (G395H/290LP; R~2700), with high spatial resolution (~0.1") and sensitivity. Thanks to the combination of the NIRSpec data and a new lensing model with accurate spectroscopic redshifts, we find that the 3"x3" field is crowded, with a lensed arc (C, $z=6.3425\pm0.0002$), two galaxies to the south (S1 and S2, $z=6.3592\pm0.0001$), two galaxies to the west (W1, $z=6.3550\pm0.0001$; W2, $z=6.3628\pm0.0001$), and two low-redshift interlopers (G1, $z=3.4806\pm0.0001$; G2, $z=2.00\pm0.01$). We present spectral fits and morpho-kinematic maps for each bright emission line from the R2700 data for all sources except G2. From a line ratio analysis, the galaxies in component C are likely powered by star formation, while we cannot rule out or confirm the presence of AGN in the other high-redshift sources. We perform gravitational lens modelling, finding evidence for a two-source composition of the lensed central object and a comparable magnification factor ($μ$=2.1-2.4) to previous work. The projected distances and velocity offsets of each galaxy suggest that they will merge within the next ~1Gyr. Finally, we examine the dust extinction-corrected SFR(Ha) of each z>6 source, finding that the total star formation ($510\pm140$Msol/yr, magnification-corrected) is distributed across the six z~6.34-6.36 objects over a region of diameter ~11kpc. Altogether, this suggests that HFLS3 is not a single starburst galaxy, but instead is a merging system of star-forming galaxies in the Epoch of Reionisation.

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arXiv2023

The ultra-dense, interacting environment of a dual AGN at z $\sim$ 3.3 revealed by JWST/NIRSpec IFS

LBQS 0302-0019 is a blue quasar (QSO) at z ~ 3.3, hosting powerful outflows, and residing in a complex environment consisting of an obscured AGN candidate, and multiple companions, all within 30 kpc in projection. We use JWST NIRSpec IFS observations to characterise the ionized gas in this complex system. We develop a procedure to correct for the spurious oscillations (or 'wiggles') in NIRSpec single-spaxel spectra, due to the spatial under-sampling of the point spread function. We perform a quasar-host decomposition with the QDeblend3D tools, and use multi-component kinematic decomposition of the optical emission line profiles to infer the physical properties of the emitting gas. The quasar-host decomposition allows us to identify i) a low-velocity component possibly tracing a warm rotating disk, with a dynamical mass Mdyn $\sim 10^{11}$ Msun and a rotation-to-random motion ratio $v_{rot}$/$σ_0 \sim 2$; ii) a spatially unresolved ionised outflow, with a velocity of $\sim$ 1000 km/s and an outflow mass rate of $\sim 10^4$ Msun/yr. We also detect eight interacting companion objects close to LBQS 0302-0019. Optical line ratios confirm the presence of a second, obscured AGN at $\sim 20$ kpc of the primary QSO; the dual AGN dominates the ionization state of the gas in the entire NIRSpec field-of-view. This work has unveiled with unprecedented detail the complex environment of this dual AGN, which includes nine interacting companions (five of which were previously unknown), all within 30 kpc of the QSO. Our results support a scenario where mergers can trigger dual AGN, and can be important drivers for rapid early SMBH growth.

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arXiv2023

Low-mass bursty galaxies in JADES efficiently produce ionising photons and could represent the main drivers of reionisation

We study galaxies in JADES Deep to study the evolution of the ionising photon production efficiency, $ξ_{\rm{ion}}$, observed to increase with redshift. We estimate $ξ_{\rm{ion}}$ for a sample of 677 galaxies at $z \sim 4 - 9$ using NIRCam photometry. Specifically, combinations of the medium and wide bands F335M-F356W and F410M-F444W to constrain emission lines that trace $ξ_{\rm{ion}}$: H$α$ and [OIII]. Additionally, we use the spectral energy distribution fitting code \texttt{Prospector} to fit all available photometry and infer galaxy properties. The flux measurements obtained via photometry are consistent with FRESCO and NIRSpec-derived fluxes. Moreover, the emission-line-inferred measurements are in tight agreement with the \texttt{Prospector} estimates. We also confirm the observed $ξ_{\rm{ion}}$ trend with redshift and M$_{\rm{UV}}$, and find: $\log ξ_{\rm{ion}} (z,\text{M}_{\rm{UV}}) = (0.05 \pm 0.02)z + (0.11 \pm 0.02) \text{M}_{\rm{UV}} + (27.33 \pm 0.37)$. We use \texttt{Prospector} to investigate correlations of $ξ_{\rm{ion}}$ with other galaxy properties. We see a clear correlation between $ξ_{\rm{ion}}$ and burstiness in the star formation history of galaxies, given by the ratio of recent to older star formation, where burstiness is more prevalent at lower stellar masses. We also convolve our $ξ_{\rm{ion}}$ relations with luminosity functions from the literature, and constant escape fractions of 10 and 20\%, to place constraints on the cosmic ionising photon budget. By combining our results, we find that if our sample is representative of the faint low-mass galaxy population, galaxies with bursty star formation are efficient enough in producing ionising photons and could be responsible for the reionisation of the Universe.

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arXiv2023

SUPER V. ALMA continuum observations of z~2 AGN and the elusive evidence of outflows influencing star formation

We study the impact of AGN ionised outflows on star formation in high-redshift AGN hosts, by combining NIR IFS observations, mapping the H$α$ emission and [OIII] outflows, with matched-resolution observations of the rest-frame FIR emission. We present high-resolution ALMA Band 7 observations of eight X-ray selected AGN at z~2 from the SUPER sample, targeting the rest-frame ~260 um continuum at ~2 kpc (0.2'') resolution. We detected 6 out of 8 targets with S/N>10 in the ALMA maps, with continuum flux densities F = 0.27-2.58 mJy and FIR half-light radii Re = 0.8-2.1 kpc. The FIR Re of our sample are comparable to other AGN and star-forming galaxies at a similar redshift from the literature. However, we find that the mean FIR size in X-ray AGN (Re = 1.16+/- 0.11 kpc) is slightly smaller than in non-AGN (Re = 1.69+/-0.13 kpc). From SED fitting, we find that the main contribution to the 260 um flux density is dust heated by star formation, with < 4% contribution from AGN-heated dust and < 1% from synchrotron emission. The majority of our sample show different morphologies for the FIR (mostly due to reprocessed stellar emission) and the ionised gas emission (H$α$ and [OIII], mostly due to AGN emission). This could be due to the different locations of dust and ionised gas, the different sources of the emission (stars and AGN), or the effect of dust obscuration. We are unable to identify any residual H$α$ emission, above that dominated by AGN, that could be attributed to star formation. Under the assumption that the FIR emission is a reliable tracer of obscured star formation, we find that the obscured star formation activity in these AGN host galaxies is not clearly affected by the ionised outflows. However, we cannot rule out that star formation suppression is happening on smaller spatial scales than the ones we probe with our observations (< 2 kpc) or on different timescales.

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arXiv2023

An investigation of the circumgalactic medium around z~2.2 AGN with ACA and ALMA

While observations of molecular gas at cosmic noon and beyond have focused on the gas within galaxies (i.e., the interstellar medium; ISM), it is also crucial to study the molecular gas reservoirs surrounding each galaxy (i.e., in the circumgalactic medium; CGM). Recent observations of galaxies and quasars hosts at high redshift (z>2) have revealed evidence for cold gaseous halos of scale r_CGM~10kpc, with one discovery of a molecular halo with r_CGM~200kpc and a molecular gas mass one order of magnitude larger than the ISM of the central galaxy. As a follow-up, we present deep ACA and ALMA observations of CO(3-2) from this source and two other quasar host galaxies at z~2.2. While we find evidence for CO emission on scales of r~10kpc, we do not find evidence for molecular gas on scales larger than r>20 kpc. Therefore, our deep data do not confirm the existence of massive molecular halos on scales of ~100 kpc for these X-ray selected quasars. As an interesting by-product of our deep observations, we obtain the tentative detection of a negative continuum signal on scales larger than r>200kpc, which might be tracing the Sunyaev-Zeldovich effect associated with the halo heated by the active galactic nucleus (AGN). If confirmed with deeper data, this could be direct evidence of the preventive AGN feedback process expected by cosmological simulations.

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arXiv2023

SUPER VII. Morphology and kinematics of H$α$ emission in AGN host galaxies at Cosmic noon using SINFONI

We present spatially resolved H$α$ properties of 21 type 1 AGN host galaxies at z$\sim$2 derived from the SUPER survey. These targets were observed with the adaptive optics capabilities of the SINFONI spectrograph, a near-infrared integral field spectrograph, that provided a median spatial resolution of 0.3 arcsec ($\sim$2 kpc). We model the H$α$ emission line profile in each pixel to investigate whether it traces gas in the narrow line region or if it is associated with star formation. To do this, we first investigate the presence of resolved H$α$ emission by removing the contribution of the AGN PSF. We find extended H$α$ emission in sixteen out of the 21 type 1 AGN host galaxies (76%). Based on the BPT diagnostics, optical line flux ratios and the line widths (FWHM), we show that the H$α$ emission in five galaxies is ionised by the AGN (30%), in four galaxies by star formation (25%) and for the rest (45%), the ionisation source is unconstrained. Two galaxies show extended H$α$ FWHM $>$600 km/s, which is interpreted as a part of an AGN-driven outflow. Morphological and kinematic maps of H$α$ emission in targets with sufficient signal-to-noise ratio suggest the presence of rotationally supported disks in six galaxies and possible presence of companions in four galaxies. In two galaxies, we find an anti-correlation between the locations of extended H$α$ emission and [OIII]-based ionised outflows, indicating possible negative feedback at play. However, in the majority of galaxies, we do not find evidence of outflows impacting H$α$ based star formation.

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arXiv2022

Evidence of extended cold molecular gas and dust halos around $\mathbf{z\sim2.3}$ Extremely Red Quasars with ALMA

Large-scale outflows are believed to be an important mechanism in the evolution of galaxies. We can determine the impact of these outflows by studying either current galaxy outflows and their effect in the galaxy or by studying the effect of past outflows on the gas surrounding the galaxy. In this work, we examine the CO(7-6), [CI]\,($^{3} \rm P_{1} \rightarrow {\rm ^3 P}_{0}$), H$_2$O 2$_{11}$--2$_{02}$ and dust continuum emission of 15 extremely red quasars (ERQs) at z$\sim$2.3 using ALMA. By investigating the radial surface brightness profiles of both the individual sources and the stacked emission, we detect extended cold gas and dust emission on scales of $\sim$14 kpc in CO(7-6), [CI](2-1), and dust continuum. This is the first time that the presence of a large amount of molecular gas was detected on large, circum-galactic medium scales around quasar host galaxies using [CI] extended emission. We estimate the dust and molecular gas mass of these halos to be 10$^{7.6}$ and 10$^{10.6}$ M$_\odot$, indicating significant dust and molecular gas reservoirs around these extreme quasars. By estimating the timescale at which this gas can reach these distances by molecular gas outflows (7-32 Myr), we conclude that these halos are a relic of past AGN or starburst activity, rather than an effect of the current episode of extreme quasar activity.

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arXiv2022

Evidence for extended gaseous reservoirs around AGN at cosmic noon from ALMA CO(3-2) observations

Gaseous outflows are key phenomena in the evolution of galaxies, as they affect star formation (either positively or negatively), eject gas from the core or disk, and directly cause mixing of pristine and processed material. Active outflows may be detected through searches for broad spectral line emission or high-velocity gas, but it is also possible to determine the presence of past outflows by searching for extended reservoirs of chemically enriched molecular gas in the circumgalactic medium (CGM) around galaxies. In this work, we examine the CO(3-2) emission of a set of seven z~2.0-2.5 AGN host galaxies, as observed with ALMA. Through a three-dimensional stacking analysis we find evidence for extended CO emission of radius r~13kpc. We extend this analysis to the HST/ACS i-band images of the sample galaxies, finding a complex small-scale (r<10kpc) morphology but no robust evidence for extended emission. In addition, the dust emission (traced by rest-frame FIR emission) shows no evidence for significant spatial extension. This indicates that the diffuse CO emission revealed by ALMA is morphologically distinct from the stellar component, and thus traces an extended reservoir of enriched gas. The presence of a diffuse, enriched molecular reservoir around this sample of AGN host galaxies at cosmic noon hints at a history of AGN-driven outflows that likely had strong effects on the star formation history of these objects.

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arXiv2022

The chemical enrichment in the early Universe as probed by JWST via direct metallicity measurements at z~8

We analyse the chemical properties of three z~8 galaxies behind the galaxy cluster SMACS J0723.3-7327, observed as part of the Early Release Observations programme of the James Webb Space Telescope (JWST). Exploiting [O III]4363 auroral line detections in NIRSpec spectra, we robustly apply the direct Te method for the very first time at such high redshift, measuring metallicities ranging from extremely metal poor (12+log(O/H)~7) to about one-third solar. We also discuss the excitation properties of these sources, and compare them with local strong-line metallicity calibrations. We find that none of the considered diagnostics match simultaneously the observed relations between metallicity and strong-line ratios for the three sources, implying that a proper re-assessment of the calibrations may be needed at these redshifts. On the mass-metallicity plane, the two galaxies at z~7.6 (log(M*/M_sun) = 8.1, 8.7) have metallicities that are consistent with the extrapolation of the mass-metallicity relation at z~2-3, while the least massive galaxy at z~8.5 (log(M*/M_sun) = 7.8) shows instead a significantly lower metallicity . The three galaxies show different level of offset relative to the Fundamental Metallicity Relation, with two of them (at z~7.6) being marginally consistent, while the z~8.5 source deviating significantly, being probably far from the smooth equilibrium between gas flows, star formation and metal enrichment in place at later epochs.

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arXiv2021

SUPER. VI. A giant molecular halo around a z~2 quasar

We present the discovery of copious molecular gas in the halo of cid_346, a $z=2.2$ quasar studied as part of the SINFONI survey for Unveiling the Physics and Effect of Radiative feedback (SUPER). New Atacama Compact Array (ACA) CO(3-2) observations detect a much higher flux (by a factor of $14\pm5$) than measured on kiloparsec scales ($r\lesssim8$ kpc) using previous snapshot Atacama Large Millimeter/submillimeter Array data. Such additional CO(3-2) emission traces a structure that extends out to $r\sim200$ kpc in projected size, as inferred through direct imaging and confirmed by an analysis of the uv visibilities. This is the most extended molecular circumgalactic medium (CGM) reservoir that has ever been mapped. It shows complex kinematics, with an overall broad line profile (FWHM $= 1000$ km/s) that is skewed towards redshifted velocities up to at least $v\sim1000$ km/s. Using the optically thin assumption, we estimate a strict lower limit for the total molecular CGM mass observed by ACA of $M_{mol}^{CGM}>10^{10}~M_{\odot}$. There is however room for up to $M^{CGM}_{mol}\sim 1.7\times 10^{12}$ $M_{\odot}$, once optically thick CO emission with $α_{\rm CO}=3.6$ $\rm M_{\odot}~(K~km~s^{-1}~pc^2)^{-1}$ and $L^{\prime}_{CO(3-2)}/L^{\prime}_{CO(1-0)}=0.5$ are assumed. Since cid_346 hosts quasar-driven ionised outflows and since there is no evidence of merging companions or an overdensity, we suggest that outflows may have played a crucial rule in seeding metal-enriched, dense gas on halo scales. However, the origin of such an extended molecular CGM remains unclear.

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arXiv2021

The impact of ionised outflows from z$\sim$2.5 quasars is not through instantaneous in-situ quenching: the evidence from ALMA and VLT/SINFONI

We present high-resolution ($\sim$2.4\,kpc) ALMA band 7 observations (rest-frame $λ\sim 250μ$m) of three powerful z$\sim$2.5 quasars ($L_{\rm bol}=10^{47.3}$-$10^{47.5}$ ergs s$^{-1}$). These targets have previously been reported as showing evidence for suppressed star formation based on cavities in the narrow H$α$ emission at the location of outflows traced with [O~{\sc iii}] emission. Here we combine the ALMA observations with a re-analysis of the VLT/SINFONI data to map the rest-frame far-infrared emission, H$α$ emission, and [O~{\sc iii}] emission. In all targets we observe high velocity [O~{\sc iii}] gas (i.e., W80$\sim$1000--2000\,km\,s$^{-1}$) across the whole galaxy. We do not identify any H$α$ emission that is free from contamination from AGN-related processes; however, based on SED analyses, we show that the ALMA data contains a significant dust-obscured star formation component in two out of the three systems. This dust emission is found to be extended over $\approx$1.5--5.5\,kpc in the nuclear regions, overlaps with the previously reported H$α$ cavities and is co-spatial with the peak in surface brightness of the [O~{\sc iii}] outflows. In summary, within the resolution and sensitivity limits of the data, we do not see any evidence for a instantaneous shut down of in-situ star formation caused directly by the outflows. However, similar to the conclusions of previous studies and based on our measured star formation rates, we do not rule out that the global host galaxy star formation could be suppressed on longer timescales by the cumulative effect of quasar episodes during the growth of these massive black holes.

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arXiv2020

SUPER III. Broad Line Region properties of AGN at z$\sim$2

The SINFONI survey for Unveiling the Physics and Effect of Radiative feedback (SUPER) was designed to conduct a blind search for AGN-driven outflows on X-ray selected AGN at redshift z$\sim$2 with high ($\sim$2 kpc) spatial resolution, and correlate them to the properties of the host galaxy and central black hole. The main aims of this paper are: a) to derive reliable estimates for the BH mass and accretion rates for the Type-1 AGN in this survey; b) to characterize the properties of the AGN driven winds in the BLR. We analyzed rest-frame optical and UV spectra of 21 Type-1 AGN. We found that the BH masses estimated from H$α$ and H$β$ lines are in agreement. We estimate BH masses in the range Log(M$\rm_{BH}/M_{\odot}$)=8.4-10.8 and Eddington ratios $\rmλ_{Edd}$ =0.04-1.3. We confirm that the CIV line width does not correlate with the Balmer lines and the peak of the line profile is blue-shifted with respect to the [OIII]-based systemic redshift. These findings support the idea that the CIV line is tracing outflowing gas in the BLR, with velocities up to $\sim$4700 km/s. We confirm the strong dependence of the BLR wind velocity with the UV-to-Xray continuum slope, L$\rm_{Bol}$ and $\rmλ_{Edd}$. We inferred BLR mass outflow rates in the range 0.005-3 M$_{\odot}$/yr, showing a correlation with the bolometric luminosity consistent with that observed for ionized winds in the NLR and X-ray winds detected in local AGN, and kinetic power $\sim$10$^{[-7:-4]}\times$ L$\rm_{Bol}$. Finally, we found an anti-correlation between the equivalent width of the [OIII] line with respect to the CIV shift, and a positive correlation with [OIII] outflow velocity. These findings, for the first time in an unbiased sample of AGN at z$\sim$2, support a scenario where BLR winds are connected to galaxy scale detected outflows, and are capable of affecting the gas in the NLR located at kpc scale.

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arXiv2020

The Star-Formation Properties of the Observed and Simulated AGN Universe: BAT vs EAGLE

In this paper we present data from 72 low redshift, hard X-ray selected AGN taken from the {\it Swift}-BAT 58 month catalogue. We utilise spectral energy distribution fitting to the optical to IR photometry in order to estimate host galaxy properties. We compare this observational sample to a volume and flux matched sample of AGN from the EAGLE hydrodynamical simulations in order to verify how accurately the simulations can reproduce observed AGN host galaxy properties. After correcting for the known +0.2 dex offset in the SFRs between EAGLE and previous observations, we find agreement in the SFR and X-ray luminosity distributions; however we find that the stellar masses in EAGLE are $0.2 - 0.4$ dex greater than the observational sample, which consequently leads to lower sSFRs. We compare these results to our previous study at high redshift, finding agreement in both the observations and simulations, whereby the widths of sSFR distributions are similar ($\sim0.4-0.6$ dex) and the median of the SFR distributions lie below the star forming main sequence by $\sim0.3-0.5$ dex across all samples. We also use EAGLE to select a sample of AGN host galaxies at high and low redshift and follow their characteristic evolution from $z=8$ to $z=0$. We find similar behaviour between these two samples, whereby star formation is quenched when the black hole goes through its phase of most rapid growth. Utilising EAGLE we find that 23\% of AGN selected at $z\sim0$ are also AGN at high redshift, and that their host galaxies are among the most massive objects in the simulation. Overall we find EAGLE reproduces the observations well, with some minor inconsistencies ($\sim$ 0.2 dex in stellar masses and $\sim$ 0.4 dex in sSFRs).

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arXiv2020

SUPER-II: Spatially resolved ionized gas kinematics and scaling relations in z~2 AGN host galaxies

The SINFONI survey for Unveiling the Physics and Effect of Radiative feedback (SUPER) aims at tracing and characterizing ionized gas outflows and their impact on star formation in a statistical sample of X-ray selected Active Galactic Nuclei (AGN) at z$\sim$2. We present the first SINFONI results for a sample of 21 Type-1 AGN spanning a wide range in bolometric luminosity (log $\mathrm{L_{bol}}$ = 45.4-47.9 erg/s). The main aims of this paper are determining the extension of the ionized gas, characterizing the occurrence of AGN-driven outflows, and linking the properties of such outflows with those of the AGN. We use Adaptive Optics-assisted SINFONI observations to trace ionized gas in the extended narrow line region using the [OIII]5007 line. We classify a target as hosting an outflow if its non-parametric velocity of the [OIII] line, $\mathrm{w_{80}}$, is larger than 600 km/s. We study 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. We detect outflows in all the Type-1 AGN sample based on the $\mathrm{w_{80}}$ value from the integrated spectrum, which is in the range 650-2700 km/s. There is a clear positive correlation between $\mathrm{w_{80}}$ and the AGN bolometric luminosity (99% correlation probability), but a weaker correlation with the black hole mass (80% correlation probability). A comparison of the PSF and the [OIII] radial profile shows that the [OIII] emission is spatially resolved for $\sim$35% of the Type-1 sample and the outflows show an extension up to $\sim$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 increase with the AGN luminosity, although for most galaxies, this fraction is less than 10%.

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arXiv2020

Establishing the impact of powerful AGN on their host galaxies

Establishing the role of active galactic nuclei (AGN) during the formation of galaxies remains one of the greatest challenges of galaxy formation theory. Towards addressing this, we summarise our recent work investigating: (1) the physical drivers of ionised outflows and (2) observational signatures of the impact by jets/outflows on star formation and molecular gas content in AGN host galaxies. We confirm a connection between radio emission and extreme ionised gas kinematics in AGN hosts. Emission-line selected AGN are significantly more likely to exhibit ionised outflows (as traced by the [O III] emission line) if the projected linear extent of the radio emission is confined within the spectroscopic aperture. Follow-up high resolution radio observations and integral field spectroscopy of 10 luminous Type 2 AGN reveal moderate power, young (or frustrated) jets interacting with the interstellar medium. We find that these sources live in highly star forming and gas rich galaxies. Additionally, by combining ALMA-derived dust maps with integral field spectroscopy for eight host galaxies of z~2 X-ray AGN, we show that H-alpha emission is an unreliable tracer of star formation. For the five targets with ionised outflows we find no dramatic in-situ shut down of the star formation. Across both of these studies we find that if these AGN do have a negative impact upon their host galaxies, it must be happening on small (unresolved) spatial scales and/or an observable galaxy-wide impact has yet to occur.

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arXiv2020

KASHz: No evidence for ionised outflows instantaneously suppressing star formation in moderate luminosity AGN at $z$$\sim$$1.4$-$2.6$

As part of our KMOS AGN Survey at High-redshift (KASHz), we present spatially-resolved VLT/KMOS and VLT/SINFONI spectroscopic data and ALMA 870$μ$m continuum imaging of eight $z$=1.4--2.6 moderate AGN ($L_{\rm 2-10 \rm kev}$ = $10^{42} - 10^{45}$ ergs s$^{-1}$). We map [OIII], H$α$ and rest-frame FIR emission to search for any spatial anti-correlation between ionised outflows (traced by the [OIII] line) and star formation (SF; traced by H$α$ 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 H$α$ is unreliable to map SF inside our AGN host galaxies based on: (i) SF rates inferred from attenuation-corrected H$α$ can lie below those inferred from FIR; (ii) the FIR continuum is more compact than the H$α$ emission by a factor of $\sim 2$ on average; (iii) in half of our sample, we observe significant spatial offsets between the FIR and H$α$ emission, with an average offset of $1.4\pm0.6$ kpc. Secondly, for the five targets with outflows we find no evidence for a spatial anti-correlation between outflows and SF using either H$α$ 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 impact on SF by ionised outflows must be subtle, either occurring on scales below our resolution, or on long timescales.

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