Evidence for powerful AGN winds at high redshift: dynamics of galactic outflows in radio galaxies during the “Quasar Era”

By N. Nesvadba, M. Lehnert, C. De Breuck, A.M.Gilbert, W. Breugel. 2008

264 citations recorded by the source corpus.

AGN feedback now appears as an attractive mechanism to resolve some of the outstanding problems with the “standard” cosmological models, in particular those related to massive galaxies. At low redshift, evidence is growing that gas cooling and star formation may be efficiently suppressed by mechanical energy input from radio sources. To directly constrain how this may influence the formation of massive galaxies near the peak in the redshift distribution of powerful quasars, z ∼ 2, we present an analysis of the emission-line kinematics of 3 powerful radio galaxies at z ∼ 2−3 (HzRGs) based on rest-frame optical integral-field spectroscopy obtained with SINFONI on the VLT. The host galaxies of powerful radio-loud AGN are among the most massive galaxies, and thus AGN feedback may have a particularly clear signature in these galaxies. We find evidence for bipolar outflows in all HzRGs, with kinetic energies that are equivalent to 0.2% of the rest-mass of the supermassive black hole. Observed total velocity offsets in the outflows are ∼800−1000 km s −1 between the blueshifted and redshifted line emission, and FWHMs ∼ 1000 km s −1 suggest strong turbulence. Line ratios allow to measure electron temperatures, ∼10 4 K from [OIII]λλλ4363, 4959, 5007 at z ∼ 2, electron densities (∼500 cm −3 ) and extinction (AV ∼ 1−4 mag). Ionized gas masses estimated from the Hα luminosity are of order 10 10 M� , similar to the molecular gas content of HzRGs, underlining that these outflows may indicate a significant phase in the evolution of the host galaxy. The total energy release of ∼10 60 erg during a dynamical time of ∼10 7 yrs corresponds to about the binding energy of a massive galaxy, similar to the prescriptions adopted in galaxy evolution models. Geometry, timescales and energy injection rates of order 10% of the kinetic energy flux of the jet suggest that the outflows are most likely driven by the radio source. The global energy density release of ∼10 57 erg s −1 Mpc −3 may also influence the subsequent evolution of the HzRG by enhancing the entropy and pressure in the surrounding halo and facilitating ram-pressure stripping of gas in satellite galaxies that may contribute to the subsequent mass assembly of the HzRG through low-dissipation “dry” mergers.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/852eb893c5127c8e9e7065f0bc5a7a9c55e80947

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Citations in the corpus

• Energetic galaxy-wide outflows in high-redshift ultraluminous infrared galaxies hosting AGN activity (2012, methodology): “This is consistent with the HzRGs of Nesvadba et al. 2008 who find R[SII]=1.0–1.1, such that the implied densities of HzRGs and highredshift ULIRGs are similar.”
• Observations of feedback from radio-quiet quasars – II. Kinematics of ionized gas nebulae (2013, methodology): “Direct and indirect evidence for powerful quasar-driven winds started emerging, both for radio-quiet (Arav et al. 2008; Moe et al. 2009; Alexander et al. 2010; Dunn et al. 2010) and radio-loud objects (Nesvadba et al. 2006, 2008) at low and high redshifts (Maiolino et al. 2012; Borguet et al. 2013).”
• Quasar feedback and the origin of radio emission in radio-quiet quasars (2014, background): “…specific examples of black-hole-driven winds have now been identified using a variety of observational techniques, both at low and at high redshifts (Nesvadba et al. 2006; Arav et al. 2008; Nesvadba et al. 2008; Moe et al. 2009; Dunn et al. 2010; Alexander et al. 2010; Harrison et al. 2012).”
• The multi-phase winds of Markarian 231: from the hot, nuclear, ultra-fast wind to the galaxy-scale, molecular outflow (2015, background): “…ionized and neutral gas with similar velocities is found on galactic scale (1-30 kpc) in a few tens AGN from the local Universe up to z=2-3 (Cano-Diaz et al. 2012, Rupke & Veilleux 2011, 2013; Harrison et al. 2014; Nesvadba et al. 2008; Harrison et al. 2012; Genzel et al. 2014, Cresci et al. 2015).”
• Discovery of extreme [O III] λ5007 Å outflows in high-redshift red quasars (2015, methodology): “…in powerful high-redshift radio galaxies is ∼1300 km s−1, i.e. two to three times smaller than that of extremely red quasars, but in the most extreme cases such as the central regions of MRC 0406−244 (Nesvadba et al. 2008) the velocities can reach values comparable to those seen in our sample.”
• Relativistic jet feedback in high-redshift galaxies – I. Dynamics (2016, background): “…of the major drivers of feedback on galactic scale, as supported by several observational evidences of jet-ISM interaction (a few recent works being Nesvadba et al. 2007, 2008, 2011; Morganti et al. 2013, 2015; Dasyra et al. 2014, 2015; Ogle, Lanz & Appleton 2014; Tadhunter et al. 2014; Lanz et…”
• DRIVING OUTFLOWS WITH RELATIVISTIC JETS AND THE DEPENDENCE OF ACTIVE GALACTIC NUCLEUS FEEDBACK EFFICIENCY ON INTERSTELLAR MEDIUM INHOMOGENEITY (2012, methodology): “Nesvadba et al. (2006, 2008) observed four HzRGs (z ∼ 2–3) with the SINFONI integral spectroscopy unit on the VLT and detected red- and blueshifted O iii emission aligned with the jet axis.”
• Jet-induced star formation in gas-rich galaxies (2011, background): “If we would increase it by a factor of ten, and if the amount of ejected mass would scale linearly with the jet power, we would reach the right order of magnitude that has been claimed by the observations (Nesvadba et al. 2008).”
• On the fundamental dichotomy in the local radio-AGN population (2012, background): “Best et al. 2000), driving bipolar winds at speeds up to thousands of km/s (e.g. Nesvadba et al. 2008).”
• The Coevolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe (2014, methodology): “Using similar techniques, galaxy-scale outflows of ionized gas have been mapped around a small sample of extremely radio-loud QSO-like AGN at z ∼ 2 (Nesvadba et al. 2006, 2008).”
• CAUSE AND EFFECT OF FEEDBACK: MULTIPHASE GAS IN CLUSTER CORES HEATED BY AGN JETS (2011, background): “Typical outflow powers are 1044 − 1045 erg s−1, with velocities ∼ 104 km s−1 and mass loading rates ∼ M yr−1 (see Crenshaw et al. 2003; Morganti et al. 2005, 2007; Nesvadba et al. 2008, 2011; Tombesi et al. 2010).”
• X-shooter reveals powerful outflows in z ∼ 1.5 X-ray selected obscured quasi-stellar objects (2014, background): “Powerful outflows sustained by relativistic and collimated jets in the hosts of luminous radio-galaxies have been commonly observed out to z∼ 4 (see e.g. Nesvadba et al. 2008, 2011; Fu & Stockton 2009).”
• AGN wind scaling relations and the co-evolution of black holes and galaxies (2017, methodology): “Nesvadba et al. (2006, 2008) found 〈ne〉 = 240−570 cm−3 and 〈ne〉 = 300−1000 cm−3 in two z ∼ 2 radio galaxies.”
• Kiloparsec-scale outflows are prevalent among luminous AGN: outflows and feedback in the context of the overall AGN population (2014, background): “…these features looks remarkably similar to the bi-conal shells of ionised gas seen in the high-redshift radio galaxy MRC 0406–244 that appear to be due to gas that has been expelled from the host galaxy by radiojets and/or star formation (Hatch et al. 2013; see also Nesvadba et al. 2008).”
• EVIDENCE FOR WIDE-SPREAD ACTIVE GALACTIC NUCLEUS-DRIVEN OUTFLOWS IN THE MOST MASSIVE z ∼ 1–2 STAR-FORMING GALAXIES (2014, background): “…AGN feedback has been observed in the so-called quasar mode in broad absorption line quasars (Arav et al. 2001, 2008, 2013; Korista et al. 2008), in type 2 AGNs (Alexander et al. 2010; Nesvadba et al. 2011; Cano Dı́az et al. 2012; Harrison et al. 2012), and in radio galaxies (Nesvadba et al. 2008).”
• THE KMOS3D SURVEY: DESIGN, FIRST RESULTS, AND THE EVOLUTION OF GALAXY KINEMATICS FROM 0.7 ⩽ z ⩽ 2.7 (2014, background): “Outflows are observed to be ubiquitous at high redshift from star formation and AGN (Nesvadba et al. 2008, 2011; Weiner et al. 2009; Shapiro et al. 2009; Steidel et al. 2010; Nestor et al. 2011; Harrison et al. 2012; Newman et al. 2012; Förster Schreiber et al. 2014; Genzel et al. 2014b).”
• Unification of X-ray winds in Seyfert galaxies: from ultra-fast outflows to warm absorbers (2012, background): “…to compare the characteristics of similar outflows found in higher redshift quasars in X-rays (Chartas et al. 2002, 2003, 2009; Giustini et al. 2011; Lanzuisi et al. 2012) and also powerful, large-scale outflows detected in other wavebands (e.g., Nesvadba et al. 2008; Sturm et al. 2011).”
• Very extended cold gas, star formation and outflows in the halo of a bright QSO at z>6 (2014, background): “5) suggest that a significant contribution from radio jets is unlikely, as radio jets tend to drive very collimated outflows with large velocity gradients across the kpc-scale jets (e.g. Nesvadba et al. 2008).”