A Survey of Kiloparsec-Scale Radio Outflows in Radio-Quiet Active Galactic Nuclei

By J. Gallimore, D. Axon, C. O’Dea, S. Baum, A. Pedlar. 2006

171 citations recorded by the source corpus.

Seyfert galaxies commonly host compact jets spanning 10-100 pc scales, but larger structures are resolved out in long-baseline aperture synthesis surveys. Previous, targeted studies showed that kiloparsec-scale radio structures (KSRs) may be a common feature of Seyfert and LINER galaxies, and the origin of KSRs may be starbursts or active galactic nuclei (AGNs). We report a new Very Large Array survey of a complete sample of Seyfert and LINER galaxies. Out of all of the surveyed radio-quiet sources, we find that 44% (19 out of 43) show extended radio structures at least 1 kpc in total extent that do not match the morphology of the disk or its associated star-forming regions. The detection rate is a lower limit owing to the combined effects of projection and resolution. The infrared colors of the KSR host galaxies are unremarkable compared to other Seyfert galaxies, and the large-scale outflows orient randomly with respect to the host galaxy axes. The KSR Seyfert galaxies instead stand out by deviating significantly from the far-infrared-radio correlation for star-forming galaxies, with tendency toward radio excess, and they are more likely to have a relatively luminous, compact radio source in the nucleus; these results argue that KSRs are powered by the AGNs rather than starbursts. The high detection rate indicates that Seyfert galaxies generate radio outflows over a significant fraction of their lifetime, which is much longer than the dynamical timescale of an AGN-powered jet but is comparable instead to the buoyancy timescale. The likely explanation is that the KSRs originate from jet plasma that has been decelerated by interaction with the nuclear interstellar medium (ISM). Based on a simple ram pressure argument, the kinetic power of the jet on kiloparsec scales is about 3 orders of magnitude weaker than the power of the jet on 10-100 pc scales. This result is consistent with the interaction model, in which case virtually all of the jet power must be lost to the ISM within the inner kiloparsec.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/ac01979482b7cdb149cbbd696293dd005281aad8

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

GIANT GAMMA-RAY BUBBLES FROM FERMI-LAT: ACTIVE GALACTIC NUCLEUS ACTIVITY OR BIPOLAR GALACTIC WIND? (2010, background): “AGN or starburst galaxies show bipolar outflows (Gallimore et al. 2006; Sharp & Bland-Hawthorn 2010).”
Radio Loudness of Active Galactic Nuclei: Observational Facts and Theoretical Implications (2006, background): “There the nuclear radio emission is usually dominant, while the extended radio emission can be due not only to jet activity, but also to starburst regions (but see Gallimore et al. 2006).”
On the origin of radio emission in radio-quiet quasars (2008, background): “These outflows can be traced to kpc scale in nearby AGN (Gallimore et al. 2006), where they produce very low power, and appear as slow buoyantly driven plasma which gradually dissipates and disappears.”
Nuclear Activity in Nearby Galaxies (2008, background): “Seyfert galaxies contain radio cores as well, but they are often accompanied by linear, jetlike features resolved on arcsecond scales (e.g., Ulvestad & Wilson 1989; Kukula et al. 1995; Ho & Ulvestad 2001; Gallimore et al. 2006).”
THE FERMI BUBBLES. I. POSSIBLE EVIDENCE FOR RECENT AGN JET ACTIVITY IN THE GALAXY (2011, background): “AGN jets have been observed in many spiral Seyfert galaxies where extended kpc-scale radio structures (KSRs) are common (Gallimore et al. 2006).”
Ejection of Supermassive Black Holes from Galaxy Cores (2007, background): “…circumstantial evidence that SMBH spin axes bear no relation to the orientations of the gas disks that surround them (Kinney et al. 2000; Gallimore et al. 2006; Borguet et al. 2007) and this is presumably even more true with respect to the directions of infalling BHs in gas-free…”
The physics of galactic winds driven by active galactic nuclei (2012, background): “Kiloparsec-scale radio synchrotron is commonly observed from AGN hosts (e.g., Baum et al. 1993; Gallimore et al. 2006) and usually interpreted as being powered by either a starburst or by a black hole jet interacting with the ISM.”
On the Nature of Seyfert Galaxies with High [O III] λ5007 Blueshifts (2008, background): “Observational evidence for outflows in AGN exists on various scales and in all wavebands from the radio (Morganti et al. 2005, Gallimore et al. 2006), to the IR (Rodriguez-Ardila et al. 2006), optical (Das et al. 2005), UV (Sulentic et al. 2007, Rodriguez Hidalgo et al. 2007, Crenshaw & Kraemer…”
Relativistic jet feedback – III. Feedback on gas discs (2018, background): “Recent papers (Gallimore et al. 2006; Combes 2017) have proposed that there is a lack of preferred orientation of jets with respect to the plane of the disk (or the galaxy’s major axis).”