Jets in FR0 radio galaxies

Abstract

The local radio-loud AGN population is dominated by compact sources named FR0s. These sources show features, for example the host type, the mass of the supermassive black hole (SMBH), and the multi-band nuclear characteristics, that are similar to those of FRI radio galaxies. However, in the radio band, while FR0 and FRI share the same nuclear properties, the kiloparsec-scale diffuse component dominant in FRI is missing in FR0s. With this project we would like to study the parsec-scale structure in FR0s in comparison with that of FRI sources. To this end we observed 18 FR0 galaxies with the VLBA at 1.5 and 5 GHz and/or with the EVN at 1.7 GHz and produced detailed images at milliarcsec resolution of their nuclear emission to study the jet and core structure. All sources have been detected but one. Four sources are unresolved, even in these high-resolution images; jets have been detected in all other sources. We derived the distribution of the jet-to-counter-jet ratio of FR0s and found that it is significantly different from that of FRIs, suggesting different jet bulk speed velocities. Combining the present data with published data of FR0 with VLBI observations, we derive that the radio structure of FR0 galaxies shows strong evidence that parsec-scale jets in FR0 sources are mildly relativistic with a bulk velocity on the order of 0.5c or less. A jet structure with a thin inner relativistic spine surrounded by a low-velocity sheath could be in agreement with the SMBH and jet launch region properties.

arXiv comment12 pages, 16 figures Accepted for the publication in Astronomy and Astrophysics

References in corpus (26)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The Co-Evolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe
• A pilot study of the radio-emitting AGN population: the emerging new class of FR0 radio-galaxies
• The local radio-galaxy population at 20 GHz
• FR0CAT: a FIRST catalog of FR0 radio galaxies
• FRICAT: A FIRST catalog of FRI radio galaxies
• High-resolution VLA observations of FR0 radio galaxies: properties and nature of compact radio sources
• Radio and spectroscopic properties of miniature radio galaxies: revealing the bulk of the radio-loud AGN population
• The Bologna Complete Sample of Nearby Radio Sources
• On the spectro-photometric properties of the bulk of the radio-loud AGN population
• Cold gas removal from the centre of a galaxy by a low-luminosity jet
• X-ray study of a sample of FR0 radio galaxies: unveiling the nature of the central engine
• The Bologna complete sample of nearby radio sources: II -- phase referenced observations of faint nuclear sources
• Parsec-scale radio structure of 14 Fanaroff-Riley type 0 radio galaxies
• Extragalactic relativistic jets
• FR0 radio galaxies and their place in the radio morphology classification
• The Powers of Relativistic Jets depend on the Spin of Accreting Supermassive Black Hole
• The LOFAR view of FR0 radio galaxies
• The LOFAR view of giant, early-type galaxies: radio emission from active nuclei and star formation
• Parsec-scale Properties of eight Fanaroff-Riley Type 0 Radio Galaxies
• Observational Properties of Jets in Active Galactic Nuclei
• The low-frequency properties of FR0 radio galaxies
• The nuclear activity and central structure of the elliptical galaxy NGC 5322
• The parsec-scale properties of the radio galaxy 4C 26.42 in the dense cooling core cluster A1795
• Reconciling AGN-star formation, the Soltan argument, and Meier's paradox
• Compact sources in the Bologna Complete Sample: high resolution VLA observations and optical data

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• The Quasar Feedback Survey: zooming into the origin of radio emission with e-MERLIN
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• The Accretion Properties and Jet Mechanisms for the Low-Excitation Radio Galaxies