scholarly journals Multiphase Outflows in High-redshift Quasar Host Galaxies

2021 ◽  
Vol 923 (1) ◽  
pp. 59
Author(s):  
Andrey Vayner ◽  
Nadia Zakamska ◽  
Shelley A. Wright ◽  
Lee Armus ◽  
Norman Murray ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
High Redshift ◽  
Coupling Efficiency ◽  
Molecular Gas ◽  
Driving Mechanism ◽  
Host Galaxies ◽  
Major Mechanism ◽  
Bolometric Luminosity ◽  
Integral Field Spectrograph ◽  
The Impact

Abstract We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of six radio-loud quasar host galaxies at z = 1.4–2.3. We combine the kiloparsec-scale resolution ALMA observations with high spatial resolution adaptive optics integral field spectrograph data of the ionized gas. We detect molecular gas emission in five quasar host galaxies and resolve the molecular interstellar medium using the CO (3–2) or CO (4–3) rotational transitions. Clumpy molecular outflows are detected in four quasar host galaxies and a merger system 21 kpc away from one quasar. Between the ionized and cold molecular gas phases, the majority of the outflowing mass is in a molecular phase, while for three out of four detected multiphase gas outflows, the majority of the kinetic luminosity and momentum flux is in the ionized phase. Combining the energetics of the multiphase outflows, we find that their driving mechanism is consistent with energy-conserving shocks produced by the impact of the quasar jets with the gas in the galaxy. By assessing the molecular gas mass to the dynamics of the outflows, we estimate a molecular gas depletion timescale of a few megayears. The gas outflow rates exceed the star formation rates, suggesting that quasar feedback is a major mechanism of gas depletion at the present time. The coupling efficiency between the kinetic luminosity of the outflows and the bolometric luminosity of the quasar of 0.1%–1% is consistent with theoretical predictions. Studying multiphase gas outflows at high redshift is important for quantifying the impact of negative feedback in shaping the evolution of massive galaxies.

scholarly journals High-redshift quasar host galaxies with adaptive optics

2005 ◽  
Vol 439 (2) ◽  
pp. 497-512 ◽  
Author(s):  
B. Kuhlbrodt ◽  
E. Örndahl ◽  
L. Wisotzki ◽  
K. Jahnke
Keyword(s):  
Adaptive Optics ◽  
High Redshift ◽  
Host Galaxies

scholarly journals SUPER

2018 ◽  
Vol 620 ◽  
pp. A82 ◽  
Author(s):  
C. Circosta ◽  
V. Mainieri ◽  
P. Padovani ◽  
G. Lanzuisi ◽  
M. Salvato ◽  
...  
Keyword(s):  
Star Formation ◽  
Adaptive Optics ◽  
High Redshift ◽  
Spectral Energy Distribution ◽  
Host Galaxy ◽  
Spectral Energy ◽  
Distribution Fitting ◽  
X Ray ◽  
Narrow Component ◽  
The Impact

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 × 109 − 2 × 1011 M⊙), star formation rates (25 − 680 M⊙ yr−1) and AGN bolometric luminosities (2 × 1044 − 8 × 1047 erg s−1), along with obscuring column densities (up to 2 × 1024 cm−2) and luminosities in the hard 2 − 10 keV band (2 × 1043 − 6 × 1045 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.

scholarly journals Simulating High-Redshift Disk Galaxies: Applications to Long Duration Gamma-Ray Burst Hosts

2008 ◽  
Vol 4 (S254) ◽  
pp. 35-40
Author(s):  
Brant E. Robertson
Keyword(s):  
Star Formation ◽  
Molecular Hydrogen ◽  
Gamma Ray ◽  
High Redshift ◽  
Disk Galaxies ◽  
Host Galaxies ◽  
Long Duration ◽  
Low Mass ◽  
Hydrodynamical Simulations ◽  
The Impact

AbstractThe efficiency of star formation governs many observable properties of the cosmological galaxy population, yet many current models of galaxy formation largely ignore the important physics of star formation and the interstellar medium (ISM). Using hydrodynamical simulations of disk galaxies that include a treatment of the molecular ISM and star formation in molecular clouds (Robertson & Kravtsov 2008), we study the influence of star formation efficiency and molecular hydrogen abundance on the properties of high-redshift galaxy populations. In this work, we focus on a model of low-mass, star forming galaxies at 1 ≲ z ≲ 2 that may host long duration gamma-ray bursts (GRBs). Observations of GRB hosts have revealed a population of faint systems with star formation properties that often differ from Lyman-break galaxies (LBGs) and more luminous high-redshift field galaxies. Observed GRB sightlines are deficient in molecular hydrogen, but it is unclear to what degree this deficiency owes to intrinsic properties of the galaxy or the impact the GRB has on its environment. We find that hydrodynamical simulations of low-stellar mass systems at high-redshifts can reproduce the observed star formation rates and efficiencies of GRB host galaxies at redshifts 1 ≲ z ≲ 2. We show that the compact structure of low-mass high-redshift GRB hosts may lead to a molecular ISM fraction of a few tenths, well above that observed in individual GRB sightlines. However, the star formation rates of observed GRB host galaxies imply molecular gas masses of 108 – 109M⊙ similar to those produced in the simulations, and may therefore imply fairly large average H2 fractions in their ISM.

scholarly journals SHARP – VI. Evidence for CO (1–0) molecular gas extended on kpc-scales in AGN star-forming galaxies at high redshift

2020 ◽  
Vol 495 (2) ◽  
pp. 2387-2407 ◽  
Author(s):  
C Spingola ◽  
J P McKean ◽  
S Vegetti ◽  
D Powell ◽  
M W Auger ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Surface Brightness ◽  
High Redshift ◽  
Host Galaxy ◽  
Molecular Gas ◽  
Host Galaxies ◽  
Gas Reservoirs ◽  
Star Forming ◽  
Radio Jets ◽  
First Time

ABSTRACT We present a study of the stellar host galaxy, CO (1–0) molecular gas distribution and AGN emission on 50–500 pc-scales of the gravitationally lensed dust-obscured AGN MG J0751+2716 and JVAS B1938+666 at redshifts 3.200 and 2.059, respectively. By correcting for the lensing distortion using a grid-based lens modelling technique, we spatially locate the different emitting regions in the source plane for the first time. Both AGN host galaxies have 300–500 pc-scale size and surface brightness consistent with a bulge/pseudo-bulge, and 2 kpc-scale AGN radio jets that are embedded in extended molecular gas reservoirs that are 5–20 kpc in size. The CO (1–0) velocity fields show structures possibly associated with discs (elongated velocity gradients) and interacting objects (off-axis velocity components). There is evidence for a decrement in the CO (1–0) surface brightness at the location of the host galaxy, which may indicate radiative feedback from the AGN, or offset star formation. We find CO–H2 conversion factors of around αCO = 1.5 ± 0.5 (K km s−1 pc2)−1, molecular gas masses of &gt;3 × 1010 M⊙, dynamical masses of ∼1011 M⊙, and gas fractions of around 60 per cent. The intrinsic CO line luminosities are comparable to those of unobscured AGN and dusty star-forming galaxies at similar redshifts, but the infrared luminosities are lower, suggesting that the targets are less efficient at forming stars. Therefore, they may belong to the AGN feedback phase predicted by galaxy formation models, because they are not efficiently forming stars considering their large amount of molecular gas.

scholarly journals Detecting Low-Order CO Emission from z ≳ 4 Quasar Host Galaxies

2006 ◽  
Vol 2 (S235) ◽  
pp. 423-423
Author(s):  
D. A. Riechers ◽  
F. Walter ◽  
C. L. Carilli ◽  
K. K. Knudsen ◽  
K.Y. Lo ◽  
...  
Keyword(s):  
High Redshift ◽  
Molecular Gas ◽  
Host Galaxies ◽  
Gas Reservoirs ◽  
Green Bank Telescope ◽  
Z Sources ◽  
Large Velocity Gradient ◽  
Atmospheric Windows ◽  
Co Emission ◽  
Gas Component

AbstractMolecular gas has now been detected in 15 z>2 QSOs. These detections are commonly obtained by observing high–J CO transitions due to their relatively high peak fluxes and observing frequencies in the millimeter atmospheric windows. However, only observations of the CO ground-state transition, CO(1–0), have the potential to trace the molecular gas at lower excitations, which may give a better estimate of the total molecular gas mass of high–z QSOs. Here we present first z>4 CO(1–0) observations obtained with the NRAO Green Bank Telescope and the MPIfR Effelsberg telescope (Riechers et al. 2006). With these two 100m telescopes, we detect the CO(1–0) transition in the high–redshift QSOs BR 1202-0725 (z = 4.7), PSS J2322+1944 (z = 4.1), and APM 08279+5255 (z = 3.9). We find that the CO/FIR luminosity ratios of these high-z sources follow the same trend as seen for low-z galaxies. Utilizing large velocity gradient (LVG) models based on previous results for higher–J CO transitions, we derive that all CO emission can be described by a single gas component and that all molecular gas appears to be concentrated in a compact nuclear region. We thus find no evidence for luminous, extended CO(1–0) components in the molecular gas reservoirs around our target quasars.

scholarly journals The Impact of Extremely Large Telescopes on the Study of the Most Luminous Stellar Objects

2007 ◽  
Vol 3 (S250) ◽  
pp. 495-502
Author(s):  
Sandro D'Odorico
Keyword(s):  
Adaptive Optics ◽  
Angular Resolution ◽  
High Redshift ◽  
Chemical Abundances ◽  
Stellar Objects ◽  
Nearby Galaxies ◽  
Infrared Wavelengths ◽  
Large Telescopes ◽  
New Generation ◽  
The Impact

AbstractThe potential advantages of the new generation of Extremely Large Telescopes are briefly summarized. When used in combination with advanced adaptive optics modules which can substantially remove the effect of atmospheric turbulence at infrared wavelengths, these telescopes will provide unique capabilities both in terms of photon collecting power (→2-4 magnitude advantage) and angular resolution (4-5 times higher than with current 8-10m telescopes). The instruments under study for the TMT and E-ELT projects are presented and compared. I discuss the impact of the ELTs on three major science topics: stellar populations in galaxies to the Virgo distance, chemical abundances of the brighter stars in nearby galaxies and high redshift SN and GRBs.

The impact of AGN on the life of their host galaxies at z ∼ 2

2019 ◽  
Vol 15 (S356) ◽  
pp. 194-198
Author(s):  
Chiara Circosta
Keyword(s):  
Star Formation ◽  
Galactic Nuclei ◽  
Molecular Gas ◽  
Host Galaxies ◽  
Gas Reservoir ◽  
Star Forming ◽  
Normal Galaxies ◽  
Two Samples ◽  
Stellar Masses ◽  
The Impact

AbstractFeedback from active galactic nuclei (AGN) is thought to be key in shaping the life cycle of host galaxies by regulating star formation. Therefore, measuring the molecular gas reservoir out of which stars form is essential to understand the impact of AGN on star formation. In this talk I present an ongoing analysis to study the CO(J = 3−2) emission in a sample of 25 AGN at z ∼ 2 using ALMA observations. The CO properties of our AGN have been compared to normal (non-AGN) star-forming galaxies. The comparison between the two samples reveals that, on average, the CO luminosities of AGN at high stellar masses (log(M*/M⊙) > 11) are 0.5 dex lower than normal galaxies. We ascribe this difference to the AGN activity, which could be able to change the conditions of the gas through, e.g., excitation, heating or removal of CO.

scholarly journals OSIRIS View of Submillimeter Galaxies: A 2–D Spectroscopic Insight to Starburst Galaxies in the High-Redshift Universe

2009 ◽  
Vol 5 (S267) ◽  
pp. 46-51
Author(s):  
K. Menéndez-Delmestre ◽  
A. W. Blain ◽  
M. Swinbank ◽  
I. Smail ◽  
S. C. Chapman ◽  
...  
Keyword(s):  
Star Formation ◽  
Adaptive Optics ◽  
High Redshift ◽  
Dust Emission ◽  
Line Emission ◽  
Spectroscopic Techniques ◽  
Star Forming ◽  
Hα Emission ◽  
Integral Field Spectrograph ◽  
Guide Star

AbstractUltra-luminous infrared galaxies (LIR > 1012L⊙) are locally rare, but appear to dominate the co-moving energy density at higher redshifts (z > 2). Many of these are optically faint, dust-obscured galaxies that have been identified by the detection of their thermal dust emission in the sub-mm. Multi-wavelength spectroscopic follow-up observations of these sub-mm galaxies (SMGs) have shown that they are massive (Mstellar ~ 1011M⊙) objects undergoing intense star-formation (SFRs ~ 102–103M⊙ yr−1) with a mean redshift of z ~ 2, coinciding with the epoch of peak quasar activity. Furthermore, the presence of AGNs in ~ 28–50% of SMGs has been unveiled in the X-ray and near-IR. When both AGN and star-formation activity are present, long-slit spectroscopic techniques face difficulties in disentangling their independent contributions from integrated spectra. We have observed Hα emission from a sample of three SMGs in the redshift range z ~ 1.4–2.4 with the integral field spectrograph OSIRIS on Keck, in conjunction with Laser Guide Star Adaptive Optics. The spatially resolved, two-dimensional spectroscopic insight that these observations provide is the only viable probe of the spatial distribution and line-of-sight motion of ionized gas within these galaxies. We detect multiple galactic-scale sub-components, distinguishing the compact, broad Hα emission arising from an AGN from the more extended narrow-line emission of star-forming regions spreading over ~ 8–17 kpc. We explore the dynamics of gas in the inner galaxy halo to improve our understanding of the internal dynamics of this enigmatic galaxy population. We find no evidence of ordered orbital motion such as would be found in a gaseous disk, but rather large velocity offsets of a few hundred kilometers per second between distinct galactic-scale sub-components. Considering the disturbed morphology of SMGs, these sub-components are likely remnants of originally independent gas-rich galaxies that are in the process of merging, hence triggering the ultraluminous SMG phase.

Distant quasar host galaxies and their environments with multi-wavelength 3D spectroscopy

2020 ◽  
Vol 15 (S359) ◽  
pp. 78-81
Author(s):  
Andrey Vayner
Keyword(s):  
Adaptive Optics ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Massive Galaxies ◽  
Star Forming ◽  
Multi Wavelength ◽  
Integral Field Spectrograph ◽  
Guide Star ◽  
Laser Guide

AbstractWe have conducted a multi-wavelength survey of distant (1.3 < z < 2.6) luminous quasars host galaxies using the Keck integral field spectrograph (IFS) OSIRIS and laser guide star adaptive optics (LGS-AO) system, ALMA, HST and VLA. Studying distant quasar host galaxies is essential for understanding the role of active galactic nuclei (AGN) feedback on the interstellar medium (ISM), and its capability of regulating the growth of massive galaxies and their supermassive black holes (SMBH). The combination of LGS-AO and OSIRIS affords the necessary spatial resolution and contrast to disentangle the bright quasar emission from that of its faint host galaxy. We resolve the nebular emission lines, [OIII], [NII],, and [SII] at a sub-kiloparsec resolution to study the distribution, kinematics, and dynamics of the warm-ionized ISM in each quasar host galaxy. The goal of the survey was to search for ionized outflows and relate their spatial extent and energetics to the star-forming properties of the host galaxy. Combining ALMA and OSIRIS, we directly test whether outflows detected with OSIRIS are affecting the molecular ISM. We find that several mechanisms are responsible for driving the outflows within our systems, including radiation pressure in low and high column density environments as well as adiabatic and isothermal shocks driven by the quasar. From line ratio diagnostics, we obtain resolved measurements of the photoionization mechanisms and the gas-phase metallicity. We find that the quasars are responsible for photoionizing the majority of the ISM with metalicities lower than that of gas photoionized by AGN in the low redshift systems. We are now obtaining detailed observations of the circumgalactic medium (CGM) of these systems with the Keck Cosmic Web Imager (KCWI). The gas in the CGM may play an essential role in the evolution of these galaxies.

Central kiloparsec of NGC 1326 observed with SINFONI

2020 ◽  
Vol 638 ◽  
pp. A53
Author(s):  
Nastaran Fazeli ◽  
Gerold Busch ◽  
Andreas Eckart ◽  
Françoise Combes ◽  
Persis Misquitta ◽  
...  
Keyword(s):  
Black Hole ◽  
Galaxy Evolution ◽  
Near Infrared ◽  
Velocity Fields ◽  
Molecular Gas ◽  
Nearby Galaxy ◽  
Stellar Content ◽  
Stellar Rotation ◽  
Supermassive Black Hole ◽  
Integral Field Spectrograph

Gas inflow processes in the vicinity of galactic nuclei play a crucial role in galaxy evolution and supermassive black hole growth. Exploring the central kiloparsec of galaxies is essential to shed more light on this subject. We present near-infrared H- and K-band results of the nuclear region of the nearby galaxy NGC 1326, observed with the integral-field spectrograph SINFONI mounted on the Very Large Telescope. The field of view covers 9″ × 9″ (650 × 650 pc2). Our work is concentrated on excitation conditions, morphology, and stellar content. The nucleus of NGC 1326 was classified as a LINER, however in our data we observed an absence of ionised gas emission in the central r ∼ 3″. We studied the morphology by analysing the distribution of ionised and molecular gas, and thereby detected an elliptically shaped, circum-nuclear star-forming ring at a mean radius of 300 pc. We estimate the starburst regions in the ring to be young with dominating ages of < 10 Myr. The molecular gas distribution also reveals an elongated east to west central structure about 3″ in radius, where gas is excited by slow or mild shock mechanisms. We calculate the ionised gas mass of 8 × 105 M⊙ completely concentrated in the nuclear ring and the warm molecular gas mass of 187 M⊙, from which half is concentrated in the ring and the other half in the elongated central structure. The stellar velocity fields show pure rotation in the plane of the galaxy. The gas velocity fields show similar rotation in the ring, but in the central elongated H2 structure they show much higher amplitudes and indications of further deviation from the stellar rotation in the central 1″ aperture. We suggest that the central 6″ elongated H2 structure might be a fast-rotating central disc. The CO(3–2) emission observations with the Atacama Large Millimeter/submillimeter Array reveal a central 1″ torus. In the central 1″ of the H2 velocity field and residual maps, we find indications for a further decoupled structure closer to a nuclear disc, which could be identified with the torus surrounding the supermassive black hole.

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