Ionized outflows in luminous type 2 AGNs atz< 0.6: no evidence for significant impact on the host galaxies

Abstract

We investigate the presence of extended ionized outflows in 18 luminous type 2 AGNs (11 quasars and 7 high luminosity Seyfert 2s) at 0.3<z<0.6 based on VLT-FORS2 spectroscopy. We infer typical lower limits on the radial sizes of the outflows R o several×100 pc and upper limits R o 1-2 kpc. Our results are inconsistent with related studies which suggest that large scale (R o ∼several-15 kpc) are ubiquitous in QSO2. We study the possible causes of discrepancy and propose that seeing smearing is the cause of the large inferred sizes. The implications in our understanding of the feedback phenomenon are important since the mass M o (through the density), mass injectionṀ o and energy injectionĖ o rates of the outflows become highly uncertain. One conclusion seems unavoidable: M o ,Ṁ o andĖ o are modest or low compared with previous estimations. We obtain typically M o (0.4-22)×10 6 M ⊙ (median 1.1×10 6 M ⊙ ) assuming n =1000 cm −3 . These are ∼10 2 -10 4 times lower than values reported in the literature. Even under the most favorable assumptions, we obtainṀ o 10 M ⊙ yr −1 in general, 100-1000 times lower than claimed in related studies. Although the uncertainties are large, it is probable that these are lower than typical star forming rates. In conclusion, no evidence is found supporting that typical outflows can affect the interstellar medium of the host galaxies accross spatial scales 1-2 kpc.

Quantifying the AGN-driven outflows in ULIRGs (QUADROS) – I: VLT/Xshooter observations of nine nearby objects

“…In general, however, even with this less conservative assumption about the true outflow velocities, the mass outflow rates and outflow kinetic powers remain significantly lower than those determined in some recent studies (Liu et al 2013;Harrison et al 2014;McElroy et al 2015;Sun et al 2017, see Table 21 for a comparison), but are consistent with those deduced by Villar-Martín et al (2016). Concentrating first on estimates ofṀ andĖ obtained using methods similar to that of this paper, the various studies make different assumptions about how the de-projected outflow velocities and radii are determined from the data.…”

“…Taking into consideration that the R [OIII] measurements are upper limits, these estimates of the outflows are notably smaller than those reported in the literature for some studies of luminous AGN at both low and high redshifts (up to 15kpc; e.g. Alexander et al 2010;Greene et al 2011;Harrison et al 2012;Harrison et al 2014;Cresci et al 2015;McElroy et al 2015;Ramos Almeida et al 2017), but are closer to those reported in Villar-Martín et al (2016) and Karouzos, Woo & Bae (2016) (a few hundred pc up to ∼2kpc).…”

Large-scale outflows in luminous QSOs revisited

“…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.…”

“…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).…”

“…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.…”