Hybrid morphology radio sources from the FIRST survey

Gawroński, M.; Marecki, A.; Kunert-Bajraszewska, M.; Kus, A. J.

doi:10.1051/0004-6361:20053996

Cited by 56 publications

(63 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Combining those two properties may explain how the hotspot became relatively subsonic to ambient medium, which leads to disruption of the collimated jet due to its weakened Mach disk. Gopal-Krishna & Wiita (2000, hereafter GKW00) show that there is a rare group of objects (<1% of extended FIRST objects; Gawroński et al 2006) that indeed exhibits two different morphological classes of the jets, and they named them HYMORS (HYbrid MOrphology Radio Source). They point out that the HYMORS class may be essential for understanding the FR I/FR II dichotomy.…”

Section: Introductionmentioning

confidence: 99%

Orientation of the cores of hybrid morphology radio sources

Ceglowski

Gawroński

Kunert-Bajraszewska

2013

A&A

Self Cite

View full text Add to dashboard Cite

Aims. The FR I/FR II dichotomy is a much debated issue in the astrophysics of extragalactic radio sources. Study of the properties of HYbrid MOrphology Radio Sources (HYMORS) may bring crucial information and lead to a step forward in understanding the origin of FR I/FR II dichotomy. HYMORS are a rare class of double-lobed radio sources where each of the two lobes clearly exhibits a different FR morphology. This article describes follow-up high resolution VLBA observations of the five discovered by us HYMORS. The main aim of the observations was to answer the questions of whether the unusual radio morphology is connected to the orientation of objects towards the observer. Methods. The milliarcsecond-scale structures are good probes of the galactic medium, the possible asymmetries, and orientation of the central engines of the sources. We obtained the high resolution radio maps of five hybrid radio morphology objects with the VLBA at C-band and L-band. Results. The cores of all five sources have been detected at both radio bands. Two of them revealed milliarcsecond core-jet structures, the next two objects showed hints of parsec-scale jets, and the last one remained point-like at both frequencies. Conclusions. We compared properties of observed milliarcsecond structures of hybrid sources with the larger scale ones previously detected with the VLA. We find that on both scales the fluxes of their central components are similar, which may indicate the lack of additional emission in the proximity of the nucleus. This suggests that jets present on the ∼1−10 kpc scale in those objects are FR II-like. When possible, the detected core-jet structures were used for estimating the core's spatial orientation. The result is that neither the FR I-like nor the FR II-like side is preferred, which may suggest that no specific spatial orientation of HYMORS is required to explain their radio morphology. Their estimated viewing angles indicate they are unbeamed objects. The 178/151 MHz luminosity of observed HYMORS exceed the traditional FR I/FR II break luminosity, indicating they have radio powers similar to FR IIs.

show abstract

Section: Introductionmentioning

confidence: 99%

Orientation of the cores of hybrid morphology radio sources

Ceglowski

Gawroński

Kunert-Bajraszewska

2013

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, asymmetries of the lobes cannot be attributed to relativistic beaming because they are not moving with relativistic velocities (Longair & Riley, 1979). A good example of a class of object where asymmetries are conspicuous, but do not result from the orientation, are the so-called HYbrid MOrphology Radio Sources (HYMORS) (Gopal-Krishna & Wiita, 2000;Gawroński et al, 2006), i.e. sources each of whose sides are a different Fanaroff-Riley (FR) type (Fanaroff & Riley, 1974).…”

Section: Introductionmentioning

confidence: 99%

Are 3C 249.1 and 3C 334 restarted quasars?

Marecki

2012

A&A

Self Cite

View full text Add to dashboard Cite

This Research Note follows up a Letter in which I posit that J1211+743 is a restarted radio source. This means that its structure, where the jet points to the relic lobe, is only apparently paradoxical. Here, I propose the same scenario and apply the same mathematical model to 3C 249.1 and 3C 334. The ultimate result of my investigation is that these two well-known radio-loud quasars can be understood best so far if it was assumed that they, too, had been restarted.

show abstract

“…Low luminosity young AGNs may develop diffuse, large-scale structures (Gawroński et al 2006;Cegłowski et al 2013) as their weak jets are disrupted before escaping their host galaxies. They may undergo disrupted evolution many times, before finally they will be able to escape the host galaxy and evolve further.…”

Section: Discussionmentioning

confidence: 99%

A VLBI survey of compact broad absorption line quasars with balnicity index BI > 0

Kunert-Bajraszewska¹,

Ceglowski²,

Roskowiński³

2015

A&A

Self Cite

View full text Add to dashboard Cite

Aims. Outflows manifest as broad absorption lines (BALs) in the quasars spectra. Although outflows are one of the most common astrophysical processes in the Universe, the BAL quasars are rare. Radio emission is another tool that can help to understand the phenomenon of BAL quasars. The aim of this paper is to study their orientation and age by very long baseline interferometry (VLBI) imaging and radio-loudness parameter distribution. Methods. We performed high resolution radio observations of a new sample of ten BAL quasars using both the Very Long Baseline Array (VLBA) and the European VLBI Network (EVN) at 5 GHz. All the selected sources have balnicity indices (BI) more than 0 and radio flux densities less than 80 mJy at 1.4 GHz. They are very compact with linear sizes of the order of a few tens of parsecs and radio luminosities at 1.4 GHz above the FR I-FR II luminosity threshold. Results. Most of the observed objects have been resolved at 5 GHz showing one-sided, probably core-jet structures, typical for quasars. We discuss in detail their age and orientation based on the radio observations. We then used the largest available sample of BAL quasars to study the relationships between the radio and optical properties in these objects. We found that (1) the strongest absorption (high values of the balnicity index BI) is connected with the lower values of the radio-loudness parameter, log R I < 1.5, and thus probably with large viewing angles; (2) the large span of the BI values in each bin of the radio-loudness parameter indicates that the orientation is only one of the factors influencing the measured absorption; (3) most of the radio-loud BAL quasars are compact, low luminosity objects with a wide range of jet power (although the highest values of BI seem to be associated with the lower values of jet power). In addition, we suggest that the short lifetime postulated for some compact active galactic nuclei could also explain the scarcity of the large-scale radio sources among BAL quasars.

show abstract

Hybrid morphology radio sources from the FIRST survey

Cited by 56 publications

References 27 publications

Orientation of the cores of hybrid morphology radio sources

Orientation of the cores of hybrid morphology radio sources

Are 3C 249.1 and 3C 334 restarted quasars?

A VLBI survey of compact broad absorption line quasars with balnicity index BI > 0

Contact Info

Product

Resources

About