Interactions between large-scale radio structures and gas in a sample of optically selected type 2 quasars

Abstract

Context. The role of radio mode feedback in non radio-loud quasars needs to be explored in depth to determine its true importance. Its effects can be identified based on the evidence of interactions between the radio structures and the ambient ionised gas. Aims. We investigate this interaction in a sample of 13 optically selected type 2 quasars (QSO2) at z < 0.2 with the Very Large Array (VLA) FIRST Survey radio detections, none of which are radio-loud. The ranges of [OIII]λ5007 and monochromatic radio luminosities are log(L[OIII]/erg s−1) ∼ 42.08–42.79 and log(P1.4 GHz/erg s−1 Hz−1) ∼ 30.08−31.76. All of them show complex optical morphologies, with signs of distortion across tens of kpc due to mergers and interactions. Methods. We searched for evidence of interactions between the radio structures and the ionised gas by characterising and comparing their morphologies. The former was traced by narrow band Hα images obtained with the GTC 10.4 m Spanish telescope and the Osiris instrument. The latter is traced by VLA radio maps obtained with A and B configurations to achieve both high resolution and brightness sensitivity. Results. The radio luminosity has an active galatic nucleus (AGN) component in 11 our of 13 QSO2, which is spatially extended in our radio data in 9 of them (jets, lobes, or other). The relative contribution of the extended radio emission to the total P1.4 GHz is in most cases in the range from 30% to 90%. The maximum sizes are in the range of dRmax of around a few to 500 kpc. The QSO2 undergoing interaction or merger events appear to be invariably associated with ionised gas spread over large spatial scales with maximum distances from the AGN in the range rmax ∼ 12−90 kpc. The morphology of the ionised gas at < 30 kpc is strongly influenced by AGN related processes. Evidence for radio-gas interactions exist in 10 out of 13 QSO2; that is, in all but one with confirmed AGN radio components. The interactions are identified across different spatial scales, from the nuclear narrow line region up to tens of kpc. Conclusions. Although this sample cannot be considered representative of the general population of QSO2, it supports the idea that large-scale low to modest power radio sources can exist in radio-quiet QSO2, which can provide a source of feedback on scales of the spheroidal component of galaxies and well into the circumgalactic medium, in systems where radiative mode feedback is expected to dominate.

Quasar feedback survey: multiphase outflows, turbulence, and evidence for feedback caused by low power radio jets inclined into the galaxy disc

“…Indeed with the increasing availability of deep, high-resolution imaging, an increasing number of systems are also showing the presence of jets (e.g. Jarvis et al 2019 ;Pierce, Tadhunter & Morganti 2020 ;Villar Mart ín et al 2021 ).…”

Quasar Feedback Survey: Multi-phase outflows, turbulence and evidence for feedback caused by low power radio jets inclined into the galaxy disk

“…Therefore, we would like to stress that for quasars and in general if 𝐿 Bol >> 𝑃 jet , jets could still be present as strong sources of feedback and hence should not be ignored (also see Villar-Martín et al 2017). Indeed with the increasing availability of deep, high resolution imaging, an increasing number of systems are also showing the presence of jets (e.g., Jarvis et al 2019;Pierce et al 2020;Villar Martín et al 2021).…”

The Quasar Feedback Survey: revealing the interplay of jets, winds, and emission-line gas in type 2 quasars with radio polarization

“…This source reveals a radio core and a diffuse southern lobe that curves slightly towards the east (black contours in Figure 5). These structures have also been detected in the ∼ 1 arcsec images of Jarvis et al (2019) andVillar Martín et al (2021). The ∼ 0.25 arcsec image of Jarvis et al (2019) detects only the core (HR:A) (cyan contours in Figure 5, right panel).…”

“…We detect a radio core and a deflected jet giving rise to the diffuse lobes in the south-east (SE) and north-west (black contours in Figure 3). These morphological features have been detected in the ∼ 1 arcsec images of Jarvis et al (2019) andVillar Martín et al (2021), with the latter also detecting additional faint knots extending beyond the SE lobe towards the east. The ∼ 0.25 arcsec image of Jarvis et al ( 2019) reveals a core-jet structure (HR:A and HR:B) extending to the south and a hotspot (HR:C) embedded in the NW lobe (cyan contours in Figure 3, bottom panels).…”

“…We detect a radio core, a north-western (NW) lobe and a curved jet connecting the two (black contours in Figure 2). The core and lobe have also been detected by Jarvis et al (2019) andVillar Martín et al (2021) in their ∼ 1 arcsec VLA images. The ∼ 0.25 arcsec image of Jarvis et al (2019) reveals a core (HR:A), a bent-jet structure to the east (HR:B) and two hotspots (HR:C and HR:D) embedded inside the ∼ 1 arcsec lobe (cyan contours in Figure 2, top right panel).…”