Compact radio sources and jet-driven AGN feedback in the early universe: constraints from integral-field spectroscopy

Abstract

Aims. To investigate the impact of radio jets during the formation epoch of their massive host galaxies, we present an analysis of two massive, log M stellar /M ∼ 10.6 and 11.3, compact radio galaxies at z = 3.5, TNJ0205+2242 and TNJ0121+1320. Their small radio sizes (R ≤ 10 kpc) are most likely a sign of youth. In particular, we compare their radio properties and gas dynamics with those in well extended radio galaxies at high redshift, which show strong evidence for powerful, jet-driven outflows of significant gas masses (M ∼ 10 9−10 M ). Methods. Our analysis combines rest-frame optical integral-field spectroscopy obtained with SINFONI on the VLT with existing radio imaging, CO(4-3) emission line spectra, and rest-frame UV longslit spectroscopy. Results.[OIII]λ5007 line emission is compact in both galaxies and lies within the region defined by the radio lobes. For TNJ0205+2242, the Lyα profile narrows significantly outside the jet radius, indicating the presence of a quiescent halo. TNJ0121+1320 has two components at a projected relative distance of ∼10 kpc and a velocity offset of ∼300 km s −1 , measured from the [OIII]λ5007 velocity map. This suggests that the fainter component is orbiting around the more massive, radio-loud galaxy. If motions are gravitational, this implies a dynamical mass of 2 × 10 11 M for the radio-loud component. Conclusions. The dynamical mass, molecular gas mass measured from the CO line emission, and radio luminosity of these two compact radio galaxies imply that compact radio sources may well develop large-scale, energetic outflows as observed in extended radio galaxies, with the potential of removing significant fractions of the ISM from the host galaxy. The absence of luminous emission line gas extending beyond the radio emission in these sources agrees with the observed timescales and outflow rates in extended radio galaxies, and adds further evidence that the energetic, large-scale outflows observed in extended radio sources (Nesvadba et al. 2006, ApJ, 650, 693) are indeed the result of influence of the radio jet.

Kinematic signatures of AGN feedback in moderately powerful radio galaxies atz~ 2 observed with SINFONI

“…With v obs = 408 km s −1 for the companion of NVSS J201943−364542, v obs = 350 km s −1 for NVSS J004000−303333, and projected distances of 24 kpc and 8 kpc, respectively, we find dynamical mass estimates of 9 × 10 11 sin −1 i M for NVSS J004000−303333 and of 3 × 10 11 sin −1 i M for NVSS J201943−364542, respectively. Both are in the range of stellar and dynamical masses estimated previously for the most powerful HzRGs (Seymour et al 2007;De Breuck et al 2010;Nesvadba et al 2007;Villar-Martín et al 2003).…”

“…This may indicate that the gas is at least partially lit up by photons originating from the AGN in the radio galaxy. The proximity to the radio galaxy may also suggest that this gas is already dominated by the gravitational potential of the radio galaxy itself, either as part of a satellite galaxy that is being accreted (e.g., Ivison et al 2008;Nesvadba et al 2007), or perhaps because it is associated with an extended stellar halo forming around the HzRG, as observed in other cases (Hatch et al 2009; see also Collet et al 2015).…”

“…The origin of broad (FWHM 1000 km s −1 ) Hα line emission at high redshift has either been attributed to winds driven by starbursts (e.g., Le Tiran et al 2011;Shapiro et al 2009;Nesvadba et al 2007) or active galactic nuclei on galaxywide scales (e.g., Alexander et al 2010;Nesvadba et al 2011b;Harrison et al 2012), or alternatively, to gas motions in the deep gravitational potential wells very near the supermassive black hole (e.g., Alexander et al 2008;Coppin et al 2008;Nesvadba et al 2011b). For galaxies like NVSS J234235−384526, and perhaps NVSS J002431−303330 and NVSS J004000−303333, which only have relatively broad [OIII] components, it is clear that the broad-line emission probes gas in the narrow-line region or outside, at larger galactocentric radii.…”

Constraints on Feedback in the Local Universe: The Relation Between Star Formation and Agn Activity in Early-Type Galaxies

“…This theoretical picture has been supported by numerous observations. The strongest evidence comes from the brightest cluster galaxies (BCGs) of cool core clusters, whose powerful radio jets have swept out cavities in the intracluster medium (ICM; Rosner & Tucker 1989;Allen et al 2001;McNamara & Nulsen 2007), while in some individual galaxies, energy transportation into the ISM via AGN-driven outflows is observed to remove gas from the central regions of the galaxy (Crenshaw et al 2003;Nesvadba et al 2007;Alexander et al 2010;Morganti et al 2013). All these show the negative effect of AGN feedback by removing/heating up the gas and eventually suppressing the star formation and regulating the galaxy growth.…”

Tracing the extreme interplay between radio jets and the ISM in IC 5063

“…Outflows have so far mainly been traced using ionized gas (see e.g. Crenshaw et al 2003;Nesvadba et al 2007;Holt et al 2009;Reeves et al 2009;Tombesi et al 2012;Harrison et al 2012). Outflow effects have often been found to be confined to the innermost nuclear regions with relatively modest associated mass outflow rates (see e.g.…”