Unraveling the Complex Structure of Agn-Driven Outflows. I. Kinematics and Sizes

Karouzos, Marios; Woo, Jong-Hak; Bae, Hyun‐Jin

doi:10.3847/0004-637x/819/2/148

Cited by 106 publications

(181 citation statements)

References 65 publications

Supporting

Mentioning

157

Contrasting

Order By: Relevance

“…However, a reliable deblending and estimation of the contrast between resolved and unresolved emission is difficult for the obscured QSOs without a simultaneous characterization of the PSF. Thus, we are not able to directly verify that effect for obscured QSOs directly with the existing observations, but Villar-Martín et al (2016) and Karouzos et al (2016) have recently also reported very compact outflow sizes of <1−2 kpc after correction for a sample of luminous obscured QSOs at z < 0.6. While a consistent picture of the systematic effects is appearing, we cannot entirely rule out that the ionized gas properties on kpc scales are intrinsically different in obscured and unobscured AGN given the different selection criteria used for the obscured QSO samples.…”

Section: Given the Enhanced Asymmetry In The [O Iii] Light Distributionmentioning

confidence: 70%

“…However, it remains unclear whether the observation of unobscured and obscured QSOs are equally affected. A direct study of beam-smearing effects for obscured QSOs is often infeasible but Villar-Martín et al (2016) and Karouzos et al (2016) have taken the beam smearing into account when analysing a sample of obscured QSOs and also report rather compact outflows size of 1-2 kpc. Given that we find [O iii] luminosity in obscured QSOs slightly enhanced compared to the AGN luminosity, the compact NLR region is not more obscured than in unobscured QSOs and makes the beam-smearing effect as important as for unobscured QSOs.…”

Section: Discussionmentioning

confidence: 99%

“…This technique was applied to various IFU observations of unobscured QSOs Christensen et al 2006;Husemann et al 2008Husemann et al , 2013bHusemann et al , 2014Carniani et al 2015;Herenz et al 2015;Liu et al 2015) enabling the study of line diagnostics and kinematics across the host galaxy without the apparent contamination of the bright unresolved NLR. Based on a large sample of luminous unobscured QSOs at z < 0.3 and luminous obscured QSOs, Husemann et al (2013b), Villar-Martín et al (2016), and Karouzos et al (2016) reported a lack of high-velocity outflows on kpc scales after deblending the unresolved NLR and ENLR. This appears to be in direct contradiction to the result of various other groups for luminous obscured QSOs (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…With the advent of optical and near-IR long-slit or integralfield unit (IFU) spectrographs on 8 m class telescopes, the ENLR kinematics has been mapped on kpc scale for luminous QSOs at low redshift z < 1 (e.g. Fu & Stockton 2009;Greene et al 2011Greene et al , 2012Rupke & Veilleux 2011;Villar-Martín et al 2011;Husemann et al 2013b;Liu et al 2013bLiu et al , 2014Liu et al , 2015Harrison et al 2014;McElroy et al 2015;Humphrey et al 2015;Villar-Martín et al 2016;Karouzos et al 2016) and high redshift z > 1 (e.g. Cano-Díaz et al 2012;Harrison et al 2012;Brusa et al 2015;Cresci et al 2015;Carniani et al 2015).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Large-scale outflows in luminous QSOs revisited

Husemann

Scharwächter

Bennert

et al. 2016

A&A

View full text Add to dashboard Cite

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.

show abstract

Section: Given the Enhanced Asymmetry In The [O Iii] Light Distributionmentioning

confidence: 70%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Large-scale outflows in luminous QSOs revisited

Husemann

Scharwächter

Bennert

et al. 2016

A&A

View full text Add to dashboard Cite

show abstract

“…The high-ionization [O iii] λ5007 emission line has been frequently used to trace the ionized gas outflows in the narrow-line region (NLR), for investigating outflow properties using individual AGNs and a large sample (Boroson 2005;Greene & Ho 2005;Crenshaw et al 2010;Bae & Woo 2014;Harrison et al 2014;Liu et al 2014;Karouzos et al 2016;Woo et al 2016). For example, based on a sample of ∼400 quasars selected from the Sloan Digital Sky Survey (SDSS), Boroson (2005) suggested that both black hole mass and Eddington ratio play a role in determining the [O iii] kinematics.…”

Section: Introductionmentioning

confidence: 99%

Outflow Kinematics Manifested by the Hα Line: Gas Outflows in Type 2 AGNs. IV.

Kang

Woo

Bae

2017

ApJ

Self Cite

View full text Add to dashboard Cite

Energetic ionized gas outflows driven by active galactic nuclei (AGN) have been studied as a key phenomenon related to AGN feedback. To probe the kinematics of the gas in the narrow line region, [O iii] λ5007 has been utilized in a number of studies, showing non-virial kinematic properties due to AGN outflows. In this paper, we statistically investigate whether the Hα emission line is influenced by AGN driven outflows, by measuring the kinematic properties based on the Hα line profile, and by comparing them with those of [O iii]. Using the spatially integrated spectra of ∼37,000 Type 2 AGNs at z < 0.3 selected from the SDSS DR7, we find a non-linear correlation between Hα velocity dispersion and stellar velocity dispersion, which reveals the presence of the non-gravitational component, especially for AGNs with a wing component in Hα. The large Hα velocity dispersion and velocity shift of luminous AGNs are clear evidence of AGN outflow impacts on hydrogen gas, while relatively smaller kinematic properties compared to those of [O iii] imply that the observed outflow effect on the Hα line is weaker than the case of [O iii].

show abstract

Formation and spatial distribution of hypervelocity stars in AGN outflows

Wang

Loeb

2018

New Astronomy

View full text Add to dashboard Cite

We study star formation within outflows driven by active galactic nuclei (AGN) as a new source of hypervelocity stars (HVSs). Recent observations revealed active star formation inside a galactic outflow at a rate of ∼ 15 M ⊙ yr −1 . We verify that the shells swept up by an AGN outflow are capable of cooling and fragmentation into cold clumps embedded in a hot tenuous gas via thermal instabilities. We show that cold clumps of ∼ 10 3 M ⊙ are formed within ∼ 10 5 yrs. As a result, stars are produced along outflow's path, endowed with the outflow speed at their formation site. These HVSs travel through the galactic halo and eventually escape into the intergalactic medium. The expected instantaneous rate of star formation inside the outflow is ∼ 4 − 5 orders of magnitude greater than the average rate associated with previously proposed mechanisms for producing HVSs, such as the Hills mechanism and three-body interaction between a star and a black hole binary. We predict the spatial distribution of HVSs formed in AGN outflows for future observational probe.

show abstract

Unraveling the Complex Structure of Agn-Driven Outflows. I. Kinematics and Sizes

Cited by 106 publications

References 65 publications

Large-scale outflows in luminous QSOs revisited

Large-scale outflows in luminous QSOs revisited

Outflow Kinematics Manifested by the Hα Line: Gas Outflows in Type 2 AGNs. IV.

Formation and spatial distribution of hypervelocity stars in AGN outflows

Contact Info

Product

Resources

About