AGN outflows and feedback twenty years on

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.Comment: Authors' version (all referee comments addressed). 7 pages + references. Published in Nature Astronom

BAT AGN Spectroscopic Survey – XIX. Type 1 versus type 2 AGN dichotomy from the point of view of ionized outflows

We present a detailed study of ionized outflows in a large sample of ∼650 hard X-ray-detected active galactic neuclei (AGNs). Using optical spectroscopy from the BAT AGN Spectroscopic Survey (BASS), we are able to reveal the faint wings of the [O III] emission lines associated with outflows covering, for the first time, an unexplored range of low AGN bolometric luminosity at low redshift (z ∼0.05). We test if and how the incidence and velocity of ionized outflow is related to AGN physical parameters: black hole mass (⁠M_(BH)⁠), gas column density (⁠N_H⁠), Eddington ratio (⁠λ_(Edd)⁠), [O III], X-ray, and bolometric luminosities. We find a higher occurrence of ionized outflows in type 1.9 (55 per cent) and type 1 AGNs (46 per cent) with respect to type 2 AGNs (24 per cent). While outflows in type 2 AGNs are evenly balanced between blue and red velocity offsets with respect to the [O III] narrow component, they are almost exclusively blueshifted in type 1 and type 1.9 AGNs. We observe a significant dependence between the outflow occurrence and accretion rate, which becomes relevant at high Eddington ratios [log(⁠λ_(Edd)⁠) ≳ −1.7]. We interpret such behaviour in the framework of covering factor-Eddington ratio dependence. We do not find strong trends of the outflow maximum velocity with AGN physical parameters, as an increase with bolometric luminosity can be only identified when including samples of AGNs at high luminosity and high redshift taken from literature

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 ± 5) than measured on kiloparsec scales (r ≲ 8 kpc) using previous snapshot Atacama Large Millimeter/submillimeter Array data. Such additional CO(3−2) emission traces a structure that extends out to r ∼ 200 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−1) that is skewed towards redshifted velocities up to at least v ∼ 1000 km s−1. Using the optically thin assumption, we estimate a strict lower limit for the total molecular CGM mass observed by ACA of MmolCGM > 1010 M⊙. There is however room for up to MmolCGM ∼ 1.7 × 1012 M⊙, once optically thick CO emission with αCO = 3.6 M⊙ (K km s−1 pc2)−1 and L′CO(3−2)/L′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

BASS. XXXV. The MBH-σ* Relation of 105 Month Swift-BAT Type 1 AGNs

We present two independent measurements of stellar velocity dispersions (sigma(star)) from the Ca II H+K lambda 3969, 3934 and Mg I b lambda 5183, 5172, 5167 region (3880-5550 angstrom) and the calcium triplet region (8350-8750 angstrom) for 173 hard X-ray-selected Type 1 active galactic nuclei (AGNs; z <= 0.08) from the 105 month Swift-BAT catalog. We construct one of the largest samples of local Type 1 AGNs that have both single-epoch virial black hole mass (M-BH) estimates and sigma(star) measurements obtained from high spectral resolution data, allowing us to test the usage of such methods for supermassive black hole studies. We find that the two independent sigma(star) measurements are highly consistent with each other, with an average offset of only 0.002 +/- 0.001 dex. Comparing M-BH estimates based on broad emission lines and stellar velocity dispersion measurements, we find that the former is systematically lower by approximate to 0.12 dex. Consequently, Eddington ratios estimated through broad-line MBH determinations are similarly biased (but in the opposite way). We argue that the discrepancy is driven by extinction in the broad-line region. We also find an anticorrelation between the offset from the M-BH-sigma(star) relation and the Eddington ratio. Our sample of Type 1 AGNs shows a shallower M-BH-sigma(star) relation (with a power-law exponent of approximate to 3.5) compared with that of inactive galaxies (with a power-law exponent of approximate to 4.5), confirming earlier results obtained from smaller samples

SUPER VII. morphology and kinematics of H alpha 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 ∼ 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 (∼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 after subtracting the AGN PSF. We find extended H α emission in 16 out of the 21 type 1 AGN host galaxies (76 per cent). Based on the BPT diagnostics, optical line flux ratios and line widths (FWHM), we show that the H α emission in five galaxies is ionized by the AGN (30 per cent), in four galaxies by star formation (25 per cent) and for the rest (45 per cent), the ionization source is unconstrained. Two galaxies show extended H α FWHM >600 km s−1, 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 discs in six galaxies and possible presence of companions in four galaxies. In two galaxies, we find an anticorrelation between the locations of extended H α emission and [O iii]-based ionized 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