MAGNUM survey: Compact jets causing large turmoil in galaxies

Abstract

Context. Outflows accelerated by active galactic nuclei (AGN) are commonly observed in the form of coherent, mildly collimated high-velocity gas directed along the AGN ionisation cones and kinetically powerful (≳1044 − 45 erg s−1) jets. Recent works found that outflows can also be accelerated by low-power (≲1044 erg s−1) jets, and the most recent cosmological simulations indicate that these are the dominant source of feedback on sub-kiloparsec scales, but little is known about their effect on the galaxy host. Aims. We study the relation between radio jets and the distribution and kinematics of the ionised gas in IC 5063, NGC 5643, NGC 1068, and NGC 1386 as part of our survey of nearby Seyfert galaxies called Measuring Active Galactic Nuclei Under MUSE Microscope (MAGNUM). All these objects host a small-scale (≲1 kpc) low-power (≲1044 erg s−1) radio jet that has small inclinations (≲45°) with respect to the galaxy disc. Methods. We employed seeing-limited optical integral field spectroscopic observations from the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope to obtain flux, kinematic, and excitation maps of the extended ionised gas. We compared these maps with archival radio images and in one case, with Chandra X-ray observations. Results. We detect a strong (up to ≳800–1000 km s−1) and extended (≳1 kpc) emission-line velocity spread perpendicular to the direction of the AGN ionisation cones and jets in all four targets. The gas excitation in this region of line-width enhancement is entirely compatible with shock ionisation. These broad and symmetric line profiles are not associated with a single coherent velocity of the gas. A ‘classical’ outflow component with net blueshifted and redshifted motions is also present, but is directed along the ionisation cones and jets. Conclusions. We interpret the observed phenomenon as due to the action of the jets perturbing the gas in the galaxy disc. These intense and extended velocity spreads perpendicular to AGN jets and cones are indeed currently only observed in galaxies hosting a low-power jet whose inclination is sufficiently low with respect to the galaxy disc to impact on and strongly affect its material. In line with cosmological simulations, our results demonstrate that low-power jets are indeed capable of affecting the host galaxy.

LeMMINGs III. The e-MERLIN legacy survey of the Palomar sample: exploring the origin of nuclear radio emission in active and inactive galaxies through the [O iii] – radio connection

“…Such nuclei are part of a large population of radio LLAGN and faint nuclear starbursts ( 10 17.6 W Hz −1 ). This result adds observational evidence that a large fraction of LLAGN (even RQ AGN) feature low-power galactic-scale jets (Webster et al 2021), which may have a tremendous impact on their hosts by continuously injecting energy, a fundamental ingredient for galaxy feedback (Morganti 2017;Jarvis et al 2019;Hardcastle & Croston 2020;Smith et al 2020b;Jarvis et al 2021;Venturi et al 2021), as supported by the state-of-the-art jet simulations (Massaglia et al 2016;Mukherjee et al 2018Mukherjee et al , 2020.…”

Jet-Induced Feedback in the [O III] Lines of Early Evolution Stage Active Galactic Nuclei

“…An alternative explanation is that the origin of this phenomenon resides in the relativistic jets crossing the ISM and interacting with it [38]. Such phenomenon, indeed, has been observed not only in NLS1s, but in several galaxies harboring compact jets [86].…”

“…This has led some authors to suggest that NLS1s may be connected with classes of young radio galaxies such as compact steep-spectrum (CSS) sources and gigahertz-peaked sources (GPS) [38,89,[96][97][98][99][100][101][102]. Indeed, several radio galaxies show signs of line shifts and broadening induced by the presence of jets [40,86,103,104], and this seems particularly common in young radio galaxies, where the jet is directly interacting with the ISM [105,106]. In this framework, the detection of a large fraction of outliers among jetted NLS1s is not surprising.…”

Two interacting galaxies hiding as one, revealed by MaNGA

“…The wide range of velocities detected in both molecular and ionised gas might correspond to a gaseous outflow, either due to the star formation triggered by the interaction or to the feedback due to the AGN in the small galaxy. It has been shown that radio jets, even when compact, can create major turmoil in galaxies, enhancing the velocity width (Venturi et al 2021). Figure 9 reveals that the wide wings are not detected in individual spectra, but appear only by stacking.…”