Evidence of powerful relativistic jets in narrow-line Seyfert 1 galaxies

Foschini, L.

doi:10.22323/1.126.0024

Cited by 46 publications

(50 citation statements)

References 111 publications

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“…The parent samples were restricted to only radio-loud objects from Komossa et al (2006);Zhou et al (2006); Yuan et al (2008);Foschini (2011), which were slightly different from ours including radio-quiet ones as well. Six radio-quiet objects are included in our sample (log RL < 1, see Col. (7) in Table 1).…”

Section: Samplementioning

confidence: 92%

A radio detection survey of narrow-line Seyfert 1 galaxies using very long baseline interferometry at 22 GHz

Doi

Oyama

Kono

et al. 2016

Publications of the Astronomical Society of Japan

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We conducted a high-sensitivity radio detection survey for forty narrow-line Seyfert 1 (NLS1) galaxies using very-long-baseline interferometry (VLBI) at 22 GHz through phase-referencing long-time integration and using a newly developing recorder with a data rate of 8 Gbps, which is a candidate of the next generation VLBI data recording systems for the Japanese VLBI Network. The baseline sensitivity was typically a few mJy. The observations resulted in a detection rate of 12/40 for our radio-selected NLS1 sample; 11 out of the detected 12 NLS1s showed inverted radio spectra between 1.4 and 22 GHz on the basis of the Very Large Array flux densities and the VLBI detections. These high fractions suggest that a compact radio core with a high brightness temperature is frequently associated with NLS1 nuclei. On the other hand, at least half of the sample indicated apparently steep spectra even with the limited VLBI sensitivity. Both the inverted and steep spectrum radio sources are included in the NLS1 population.

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Section: Samplementioning

confidence: 92%

A radio detection survey of narrow-line Seyfert 1 galaxies using very long baseline interferometry at 22 GHz

Doi

Oyama

Kono

et al. 2016

Publications of the Astronomical Society of Japan

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“…In the case of radio-loud NLS1, that have been mentioned in the introduction, their radio power comparable to PKS 1814-637 (see e.g. Yuan et al 2008;Foschini 2011, and references therein) is likely due to their radio emission is dominated by a beamed jet emission. Furthermore, in general the host galaxies of radio-loud NLS1 have not been yet well characterised and, therefore, it is not clear that these object are host by disk galaxies.…”

Section: Link To Seyfert Galaxiesmentioning

confidence: 98%

“…Furthermore, in general the host galaxies of radio-loud NLS1 have not been yet well characterised and, therefore, it is not clear that these object are host by disk galaxies. Two examples (see Zhou et al 2007;Foschini 2011) suggest that this could be the case at least for some of them. If this is confirmed for a larger sample, it may indicate a possible, interesting link between this group of object and objects like PKS 1814-637.…”

Section: Link To Seyfert Galaxiesmentioning

confidence: 99%

“…Interestingly, radio-loud narrow line Seyfert 1 (NLS1) galaxies can reach radio power comparable to PKS 1814-637 (see e.g. Foschini 2011, and references therein) but because their radio emission is likely dominated by a beamed jet emission, their intrinsic jet (and extended radio lobe powers) might be orders of magnitude lower, making them more similar to Seyferts or low power FRIs. Because of all this, PKS 1814-637 stands out as a particularly interesting object.…”

Section: Introductionmentioning

confidence: 99%

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PKS 1814-637: a powerful radio-loud AGN in a disk galaxy

Morganti

Holt

Tadhunter

et al. 2011

A&A

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We present a detailed study of PKS 1814-637, a rare case of powerful radio source (P 5 GHz = 4.1 × 10 25 W Hz −1 ) hosted by a disk galaxy. Optical images have been used to model the host galaxy morphology confirming it to be dominated by a strong (and warped) disk component that is observed close to edge-on to the line of sight. This is the first radio galaxy found to reside in a disk dominated galaxy with radio luminosity equivalent to powerful FRII objects. At radio wavelengths, PKS 1814-637 is about 480 pc in diameter and it is classified as a compact steep spectrum (CSS) source; such sources are usually considered to be radio sources observed in the early stages of their evolution. However, the optical and mid-IR spectroscopic properties of PKS1814-637 show more in common with Seyfert galaxies than they do with radio galaxies, with the detection of H 2 , and PAH emission features, along with HI and silicate absorption features, providing evidence for a rich ISM which is likely to be related to the disk morphology of the host galaxy. We argue that the interaction between the radio plasma and the rich ISM in this and similar objects may have boosted their radio emission, allowing them to more easily enter flux limited samples of radio sources. In this case, PKS 1814-637 represents a type of "imposter": an intrinsically low power object that is selected in a radio flux limited sample because of the unusually efficient conversion of jet power into radio emission. This would make PKS 1814-637 an extreme example of the effects of jet-cloud interactions in galaxies containing a rich ISM, and perhaps a missing link between radio galaxies and radio-loud Seyfert galaxies. However, it is unlikely that jet-cloud interactions alone can account for the unusually powerful radio emission compared to Seyfert galaxies, and it is probable that the jet in PKS 1814-637 is also intrinsically more powerful than in typical Seyfert galaxies, perhaps due to a higher bulge and black hole mass. The estimated BH mass is indeed higher than the majority of Seyfert galaxies in the local Universe. We speculate that sources similar to PKS1814-637 are likely to be more common at high redshifts, because of the enhanced probability at earlier epochs of triggering radio sources in moderately massive bulges that are also gas-rich.

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“…NLS1s have many properties associated with weak or absent jets (e.g., Lacy et al 2001;Véron-Cetty & Véron 2001): they lie at the low end of the AGN black hole mass range (10 5 −10 8 M ⊙ ; e.g., Zhou et al 2006), accrete at a substantial fraction of the Eddington limit (e.g., Boller et al 1996), and are likely found in spiral or disk host galaxies (Ohta et al 2007). However, about 7% are radio loud (Komossa et al 2006) and among these, evidence of jets in these sources has been found, including from Ackermann et al (2011) or Foschini (2011.…”

Section: Introductionmentioning

confidence: 99%

The parsec-scale structure, kinematics, and polarization of radio-loud narrow-line Seyfert 1 galaxies

Richards¹,

Lister²,

Savolainen³

et al. 2014

Proc. IAU

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Abstract. Several narrow-line Seyfert 1 galaxies (NLS1s) have now been detected in gamma rays, providing firm evidence that at least some of this class of active galactic nuclei (AGN) produce relativistic jets. The presence of jets in NLS1s is surprising, as these sources are typified by comparatively small black hole masses and near-or super-Eddington accretion rates. This challenges the current understanding of the conditions necessary for jet production. Comparing the properties of the jets in NLS1s with those in more familiar jetted systems is thus essential to improve jet production models. We present early results from our campaign to monitor the kinematics and polarization of the parsec-scale jets in a sample of 15 NLS1s through multifrequency observations with the Very Long Baseline Array. These observations are complemented by fast-cadence 15 GHz monitoring with the Owens Valley Radio Observatory 40 m telescope and optical spectroscopic monitoring with with the 2 m class telescope at the Guillermo Haro Astrophysics Observatory in Cananea, Mexico.

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Evidence of powerful relativistic jets in narrow-line Seyfert 1 galaxies

Cited by 46 publications

References 111 publications

A radio detection survey of narrow-line Seyfert 1 galaxies using very long baseline interferometry at 22 GHz

A radio detection survey of narrow-line Seyfert 1 galaxies using very long baseline interferometry at 22 GHz

PKS 1814-637: a powerful radio-loud AGN in a disk galaxy

The parsec-scale structure, kinematics, and polarization of radio-loud narrow-line Seyfert 1 galaxies

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