Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS)

Gürkan, Gülay; Croston, Judith; Hardcastle, Martin J.; Mahatma, Vijay; Mingo, Beatriz and Williams, Wendy L. (2022). Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS). Galaxies, 10(1), article no. 2.

DOI: https://doi.org/10.3390/galaxies10010002

Abstract

The radiative and jet power in active galactic nuclei is generated by accretion of material on to supermassive galactic-centre black holes. For quasars, where the radiative power is by definition very high, objects with high radio luminosities form 10 per cent of the population, although it is not clear whether this is a stable phase. Traditionally, quasars with high radio luminosities have been thought to present jets with edge-brightened morphology (Fanaroff-Riley II—FR II) due to the limitations of previous radio surveys (i.e., FRIs were not observed as part of the quasar population). The LOw Frequency ARray (LOFAR) Two-metre Sky Survey (LoTSS) with its unprecedented sensitivity and resolution covering wide sky areas has enabled the first systematic selection and investigation of quasars with core-brightened morphology (Fanaroff-Riley I—FR). We carried out a Very Large Array (VLA) snapshot survey to reveal inner structures of jets in selected quasar candidates; 15 (25 per cent) out of 60 sources show clear inner jet structures that are diagnostic of FRI jets and 13 quasars (∼22 per cent) show extended structures similar to those of FRI jets. Black hole masses and Eddington ratios do not show a clear difference between FRI and FRII quasars. FRII quasars tend to have higher jet powers than FRI quasars. Our results show that the occurrence of FRI jets in powerful radiatively efficient systems is not common, probably mainly due to two factors: galaxy environment and jet power.

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About

• Item ORO ID
• 81351
• Item Type
• Journal Item
• ISSN
• 2075-4434
• Project Funding Details

• Funded Project Name	Project ID	Funding Body
  Jet energy injection in galaxy groups and clusters - transfer of CG funding (Transfer in)	ST/R00109X/1	STFC (Science & Technology Facilities Council)
  Jet physics and impact via LOFAR extragalactic surveys	ST/R000794/1	STFC (Science & Technology Facilities Council)
  Not Set	ST/T000295/1	STFC (Science & Technology Facilities Council)

• Keywords
• galaxies; quasars; radio continuum; active galactic nuclei; galaxy evolution
• Academic Unit or School
• Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
  Faculty of Science, Technology, Engineering and Mathematics (STEM)
• Copyright Holders
• © 2021 The Authors
• SWORD Depositor
• Jisc Publications-Router
• Depositing User
• Jisc Publications-Router