Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS)
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 c...
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| Format: | Article |
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MDPI AG
2021-12-01
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| Series: | Galaxies |
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| Online Access: | https://www.mdpi.com/2075-4434/10/1/2 |
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| author | Gülay Gürkan Judith Croston Martin J. Hardcastle Vijay Mahatma Beatriz Mingo Wendy L. Williams |
| author_facet | Gülay Gürkan Judith Croston Martin J. Hardcastle Vijay Mahatma Beatriz Mingo Wendy L. Williams |
| author_sort | Gülay Gürkan |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-03-09T21:54:47Z |
| format | Article |
| id | doaj.art-5f235e3369b04c05a675c2246b2e632b |
| institution | Directory Open Access Journal |
| issn | 2075-4434 |
| language | English |
| last_indexed | 2024-03-09T21:54:47Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Galaxies |
| spelling | doaj.art-5f235e3369b04c05a675c2246b2e632b2023-11-23T20:00:12ZengMDPI AGGalaxies2075-44342021-12-01101210.3390/galaxies10010002Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS)Gülay Gürkan0Judith Croston1Martin J. Hardcastle2Vijay Mahatma3Beatriz Mingo4Wendy L. Williams5Thüringer Landessternwarte Tautenburg (TLS), Sternwarte 5, D-07778 Tautenburg, GermanySchool of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UKCentre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UKThüringer Landessternwarte Tautenburg (TLS), Sternwarte 5, D-07778 Tautenburg, GermanySchool of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UKLeiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden, The NetherlandsThe 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.https://www.mdpi.com/2075-4434/10/1/2galaxiesquasarsradio continuumactive galactic nucleigalaxy evolution |
| spellingShingle | Gülay Gürkan Judith Croston Martin J. Hardcastle Vijay Mahatma Beatriz Mingo Wendy L. Williams Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS) Galaxies galaxies quasars radio continuum active galactic nuclei galaxy evolution |
| title | Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS) |
| title_full | Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS) |
| title_fullStr | Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS) |
| title_full_unstemmed | Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS) |
| title_short | Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS) |
| title_sort | finding rare quasars vla snapshot continuum survey of fri quasar candidates selected from the lofar two metre sky survey lotss |
| topic | galaxies quasars radio continuum active galactic nuclei galaxy evolution |
| url | https://www.mdpi.com/2075-4434/10/1/2 |
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